summaryrefslogtreecommitdiff
path: root/net
AgeCommit message (Collapse)Author
22 hoursarp: do not assume dev_hard_header() does not change skb->headEric Dumazet
arp_create() is the only dev_hard_header() caller making assumption about skb->head being unchanged. A recent commit broke this assumption. Initialize @arp pointer after dev_hard_header() call. Fixes: db5b4e39c4e6 ("ip6_gre: make ip6gre_header() robust") Reported-by: syzbot+58b44a770a1585795351@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260107212250.384552-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
22 hoursMerge tag 'wireless-2026-01-08' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless Johannes Berg says: ==================== Couple of fixes: - mac80211: - long-standing injection bug due to chanctx rework - more recent interface iteration issue - collect statistics before removing stations - hwsim: - fix NAN frequency typo (potential NULL ptr deref) - fix locking of radio lock (needs softirqs disabled) - wext: - ancient issue with compat and events copying some uninitialized stack data to userspace * tag 'wireless-2026-01-08' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless: wifi: mac80211: collect station statistics earlier when disconnect wifi: mac80211: restore non-chanctx injection behaviour wifi: mac80211_hwsim: disable BHs for hwsim_radio_lock wifi: mac80211: don't iterate not running interfaces wifi: mac80211_hwsim: fix typo in frequency notification wifi: avoid kernel-infoleak from struct iw_point ==================== Link: https://patch.msgid.link/20260108140141.139687-3-johannes@sipsolutions.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
22 hoursnet: do not write to msg_get_inq in calleeWillem de Bruijn
NULL pointer dereference fix. msg_get_inq is an input field from caller to callee. Don't set it in the callee, as the caller may not clear it on struct reuse. This is a kernel-internal variant of msghdr only, and the only user does reinitialize the field. So this is not critical for that reason. But it is more robust to avoid the write, and slightly simpler code. And it fixes a bug, see below. Callers set msg_get_inq to request the input queue length to be returned in msg_inq. This is equivalent to but independent from the SO_INQ request to return that same info as a cmsg (tp->recvmsg_inq). To reduce branching in the hot path the second also sets the msg_inq. That is WAI. This is a fix to commit 4d1442979e4a ("af_unix: don't post cmsg for SO_INQ unless explicitly asked for"), which fixed the inverse. Also avoid NULL pointer dereference in unix_stream_read_generic if state->msg is NULL and msg->msg_get_inq is written. A NULL state->msg can happen when splicing as of commit 2b514574f7e8 ("net: af_unix: implement splice for stream af_unix sockets"). Also collapse two branches using a bitwise or. Cc: stable@vger.kernel.org Fixes: 4d1442979e4a ("af_unix: don't post cmsg for SO_INQ unless explicitly asked for") Link: https://lore.kernel.org/netdev/willemdebruijn.kernel.24d8030f7a3de@gmail.com/ Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260106150626.3944363-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
22 hoursnet/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in ↵Xiang Mei
qfq_reset `qfq_class->leaf_qdisc->q.qlen > 0` does not imply that the class itself is active. Two qfq_class objects may point to the same leaf_qdisc. This happens when: 1. one QFQ qdisc is attached to the dev as the root qdisc, and 2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get() / qdisc_put()) and is pending to be destroyed, as in function tc_new_tfilter. When packets are enqueued through the root QFQ qdisc, the shared leaf_qdisc->q.qlen increases. At the same time, the second QFQ qdisc triggers qdisc_put and qdisc_destroy: the qdisc enters qfq_reset() with its own q->q.qlen == 0, but its class's leaf qdisc->q.qlen > 0. Therefore, the qfq_reset would wrongly deactivate an inactive aggregate and trigger a null-deref in qfq_deactivate_agg: [ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 0.903571] #PF: supervisor write access in kernel mode [ 0.903860] #PF: error_code(0x0002) - not-present page [ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0 [ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI [ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE [ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 [ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2)) [ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0 Code starting with the faulting instruction =========================================== 0: 0f 84 4d 01 00 00 je 0x153 6: 48 89 70 18 mov %rsi,0x18(%rax) a: 8b 4b 10 mov 0x10(%rbx),%ecx d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx 14: 48 8b 78 08 mov 0x8(%rax),%rdi 18: 48 d3 e2 shl %cl,%rdx 1b: 48 21 f2 and %rsi,%rdx 1e: 48 2b 13 sub (%rbx),%rdx 21: 48 8b 30 mov (%rax),%rsi 24: 48 d3 ea shr %cl,%rdx 27: 8b 4b 18 mov 0x18(%rbx),%ecx ... [ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246 [ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000 [ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000 [ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000 [ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880 [ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000 [ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0 [ 0.910247] PKRU: 55555554 [ 0.910391] Call Trace: [ 0.910527] <TASK> [ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485) [ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036) [ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076) [ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447) [ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958) [ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861) [ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550) [ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) [ 0.912296] ? __alloc_skb (net/core/skbuff.c:706) [ 0.912484] netlink_sendmsg (net/netlink/af_netlink.c:1894) [ 0.912682] sock_write_iter (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1) net/socket.c:1195 (discriminator 1)) [ 0.912880] vfs_write (fs/read_write.c:593 fs/read_write.c:686) [ 0.913077] ksys_write (fs/read_write.c:738) [ 0.913252] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) [ 0.913438] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131) [ 0.913687] RIP: 0033:0x424c34 [ 0.913844] Code: 89 02 48 c7 c0 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d 2d 44 09 00 00 74 13 b8 01 00 00 00 0f 05 9 Code starting with the faulting instruction =========================================== 0: 89 02 mov %eax,(%rdx) 2: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax 9: eb bd jmp 0xffffffffffffffc8 b: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 12: 00 00 00 15: 90 nop 16: f3 0f 1e fa endbr64 1a: 80 3d 2d 44 09 00 00 cmpb $0x0,0x9442d(%rip) # 0x9444e 21: 74 13 je 0x36 23: b8 01 00 00 00 mov $0x1,%eax 28: 0f 05 syscall 2a: 09 .byte 0x9 [ 0.914807] RSP: 002b:00007ffea1938b78 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 [ 0.915197] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000424c34 [ 0.915556] RDX: 000000000000003c RSI: 000000002af378c0 RDI: 0000000000000003 [ 0.915912] RBP: 00007ffea1938bc0 R08: 00000000004b8820 R09: 0000000000000000 [ 0.916297] R10: 0000000000000001 R11: 0000000000000202 R12: 00007ffea1938d28 [ 0.916652] R13: 00007ffea1938d38 R14: 00000000004b3828 R15: 0000000000000001 [ 0.917039] </TASK> [ 0.917158] Modules linked in: [ 0.917316] CR2: 0000000000000000 [ 0.917484] ---[ end trace 0000000000000000 ]--- [ 0.917717] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2)) [ 0.917978] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0 Code starting with the faulting instruction =========================================== 0: 0f 84 4d 01 00 00 je 0x153 6: 48 89 70 18 mov %rsi,0x18(%rax) a: 8b 4b 10 mov 0x10(%rbx),%ecx d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx 14: 48 8b 78 08 mov 0x8(%rax),%rdi 18: 48 d3 e2 shl %cl,%rdx 1b: 48 21 f2 and %rsi,%rdx 1e: 48 2b 13 sub (%rbx),%rdx 21: 48 8b 30 mov (%rax),%rsi 24: 48 d3 ea shr %cl,%rdx 27: 8b 4b 18 mov 0x18(%rbx),%ecx ... [ 0.918902] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246 [ 0.919198] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000 [ 0.919559] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 0.919908] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000 [ 0.920289] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000 [ 0.920648] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880 [ 0.921014] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000 [ 0.921424] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.921710] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0 [ 0.922097] PKRU: 55555554 [ 0.922240] Kernel panic - not syncing: Fatal exception [ 0.922590] Kernel Offset: disabled Fixes: 0545a3037773 ("pkt_sched: QFQ - quick fair queue scheduler") Signed-off-by: Xiang Mei <xmei5@asu.edu> Link: https://patch.msgid.link/20260106034100.1780779-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski <kuba@kernel.org>
26 hourswifi: mac80211: collect station statistics earlier when disconnectBaochen Qiang
In __sta_info_destroy_part2(), station statistics are requested after the IEEE80211_STA_NONE -> IEEE80211_STA_NOTEXIST transition. This is problematic because the driver may be unable to handle the request due to the STA being in the NOTEXIST state (i.e. if the driver destroys the underlying data when transitioning to NOTEXIST). Move the statistics collection to before the state transition to avoid this issue. Signed-off-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com> Link: https://patch.msgid.link/20251222-mac80211-move-station-stats-collection-earlier-v1-1-12cd4e42c633@oss.qualcomm.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
26 hourswifi: mac80211: restore non-chanctx injection behaviourJohannes Berg
During the transition to use channel contexts throughout, the ability to do injection while in monitor mode concurrent with another interface was lost, since the (virtual) monitor won't have a chanctx assigned in this scenario. It's harder to fix drivers that actually transitioned to using channel contexts themselves, such as mt76, but it's easy to do those that are (still) just using the emulation. Do that. Cc: stable@vger.kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=218763 Reported-and-tested-by: Oscar Alfonso Diaz <oscar.alfonso.diaz@gmail.com> Fixes: 0a44dfc07074 ("wifi: mac80211: simplify non-chanctx drivers") Link: https://patch.msgid.link/20251216105242.18366-2-johannes@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com>
26 hourswifi: mac80211: don't iterate not running interfacesMiri Korenblit
for_each_chanctx_user_* was introdcued as a replacement for for_each_sdata_link, which visits also other chanctx users that are not link. for_each_sdata_link skips not running interfaces, do the same for for_each_chanctx_user_* Fixes: 1ce954c98b89 ("wifi: mac80211: add and use chanctx usage iteration") Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com> Link: https://patch.msgid.link/20260107143736.55c084e2a976.I38b7b904a135dadca339321923b501b2c2c5c8c0@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com>
26 hourswifi: avoid kernel-infoleak from struct iw_pointEric Dumazet
struct iw_point has a 32bit hole on 64bit arches. struct iw_point { void __user *pointer; /* Pointer to the data (in user space) */ __u16 length; /* number of fields or size in bytes */ __u16 flags; /* Optional params */ }; Make sure to zero the structure to avoid disclosing 32bits of kernel data to user space. Fixes: 87de87d5e47f ("wext: Dispatch and handle compat ioctls entirely in net/wireless/wext.c") Reported-by: syzbot+bfc7323743ca6dbcc3d3@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/695f83f3.050a0220.1c677c.0392.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260108101927.857582-1-edumazet@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
3 daysnet/sched: act_api: avoid dereferencing ERR_PTR in tcf_idrinfo_destroyShivani Gupta
syzbot reported a crash in tc_act_in_hw() during netns teardown where tcf_idrinfo_destroy() passed an ERR_PTR(-EBUSY) value as a tc_action pointer, leading to an invalid dereference. Guard against ERR_PTR entries when iterating the action IDR so teardown does not call tc_act_in_hw() on an error pointer. Fixes: 84a7d6797e6a ("net/sched: acp_api: no longer acquire RTNL in tc_action_net_exit()") Link: https://syzkaller.appspot.com/bug?extid=8f1c492ffa4644ff3826 Reported-by: syzbot+8f1c492ffa4644ff3826@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=8f1c492ffa4644ff3826 Signed-off-by: Shivani Gupta <shivani07g@gmail.com> Link: https://patch.msgid.link/20260105005905.243423-1-shivani07g@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
3 daysudp: call skb_orphan() before skb_attempt_defer_free()Eric Dumazet
Standard UDP receive path does not use skb->destructor. But skmsg layer does use it, since it calls skb_set_owner_sk_safe() from udp_read_skb(). This then triggers this warning in skb_attempt_defer_free(): DEBUG_NET_WARN_ON_ONCE(skb->destructor); We must call skb_orphan() to fix this issue. Fixes: 6471658dc66c ("udp: use skb_attempt_defer_free()") Reported-by: syzbot+3e68572cf2286ce5ebe9@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/695b83bd.050a0220.1c9965.002b.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260105093630.1976085-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
4 daysnet: fix memory leak in skb_segment_list for GRO packetsMohammad Heib
When skb_segment_list() is called during packet forwarding, it handles packets that were aggregated by the GRO engine. Historically, the segmentation logic in skb_segment_list assumes that individual segments are split from a parent SKB and may need to carry their own socket memory accounting. Accordingly, the code transfers truesize from the parent to the newly created segments. Prior to commit ed4cccef64c1 ("gro: fix ownership transfer"), this truesize subtraction in skb_segment_list() was valid because fragments still carry a reference to the original socket. However, commit ed4cccef64c1 ("gro: fix ownership transfer") changed this behavior by ensuring that fraglist entries are explicitly orphaned (skb->sk = NULL) to prevent illegal orphaning later in the stack. This change meant that the entire socket memory charge remained with the head SKB, but the corresponding accounting logic in skb_segment_list() was never updated. As a result, the current code unconditionally adds each fragment's truesize to delta_truesize and subtracts it from the parent SKB. Since the fragments are no longer charged to the socket, this subtraction results in an effective under-count of memory when the head is freed. This causes sk_wmem_alloc to remain non-zero, preventing socket destruction and leading to a persistent memory leak. The leak can be observed via KMEMLEAK when tearing down the networking environment: unreferenced object 0xffff8881e6eb9100 (size 2048): comm "ping", pid 6720, jiffies 4295492526 backtrace: kmem_cache_alloc_noprof+0x5c6/0x800 sk_prot_alloc+0x5b/0x220 sk_alloc+0x35/0xa00 inet6_create.part.0+0x303/0x10d0 __sock_create+0x248/0x640 __sys_socket+0x11b/0x1d0 Since skb_segment_list() is exclusively used for SKB_GSO_FRAGLIST packets constructed by GRO, the truesize adjustment is removed. The call to skb_release_head_state() must be preserved. As documented in commit cf673ed0e057 ("net: fix fraglist segmentation reference count leak"), it is still required to correctly drop references to SKB extensions that may be overwritten during __copy_skb_header(). Fixes: ed4cccef64c1 ("gro: fix ownership transfer") Signed-off-by: Mohammad Heib <mheib@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260104213101.352887-1-mheib@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
4 daysnet/sched: act_mirred: Fix leak when redirecting to self on egressJamal Hadi Salim
Whenever a mirred redirect to self on egress happens, mirred allocates a new skb (skb_to_send). The loop to self check was done after that allocation, but was not freeing the newly allocated skb, causing a leak. Fix this by moving the if-statement to before the allocation of the new skb. The issue was found by running the accompanying tdc test in 2/2 with config kmemleak enabled. After a few minutes the kmemleak thread ran and reported the leak coming from mirred. Fixes: 1d856251a009 ("net/sched: act_mirred: fix loop detection") Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/20260101135608.253079-2-jhs@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
4 daysvsock: Make accept()ed sockets use custom setsockopt()Michal Luczaj
SO_ZEROCOPY handling in vsock_connectible_setsockopt() does not get called on accept()ed sockets due to a missing flag. Flip it. Fixes: e0718bd82e27 ("vsock: enable setting SO_ZEROCOPY") Signed-off-by: Michal Luczaj <mhal@rbox.co> Link: https://patch.msgid.link/20251229-vsock-child-sock-custom-sockopt-v2-1-64778d6c4f88@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysMerge tag 'nf-26-01-02' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf Florian Westphal says: ==================== netfilter: updates for net The following patchset contains Netfilter fixes for *net*: 1) Fix overlap detection for nf_tables with concatenated ranges. There are cases where element could not be added due to a conflict with existing range, while kernel reports success to userspace. 2) update selftest to cover this bug. 3) synproxy update path should use READ/WRITE once as we replace config struct while packet path might read it in parallel. This relies on said config struct to fit sizeof(long). From Fernando Fernandez Mancera. 4) Don't return -EEXIST from xtables in module load path, a pending patch to module infra will spot a warning if this happens. From Daniel Gomez. 5) Fix a memory leak in nf_tables when chain hits 2**32 users and rule is to be hw-offloaded, from Zilin Guan. 6) Avoid infinite list growth when insert rate is high in nf_conncount, also from Fernando. * tag 'nf-26-01-02' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: nf_conncount: update last_gc only when GC has been performed netfilter: nf_tables: fix memory leak in nf_tables_newrule() netfilter: replace -EEXIST with -EBUSY netfilter: nft_synproxy: avoid possible data-race on update operation selftests: netfilter: nft_concat_range.sh: add check for overlap detection bug netfilter: nft_set_pipapo: fix range overlap detection ==================== Link: https://patch.msgid.link/20260102114128.7007-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysinet: frags: drop fraglist conntrack referencesFlorian Westphal
Jakub added a warning in nf_conntrack_cleanup_net_list() to make debugging leaked skbs/conntrack references more obvious. syzbot reports this as triggering, and I can also reproduce this via ip_defrag.sh selftest: conntrack cleanup blocked for 60s WARNING: net/netfilter/nf_conntrack_core.c:2512 [..] conntrack clenups gets stuck because there are skbs with still hold nf_conn references via their frag_list. net.core.skb_defer_max=0 makes the hang disappear. Eric Dumazet points out that skb_release_head_state() doesn't follow the fraglist. ip_defrag.sh can only reproduce this problem since commit 6471658dc66c ("udp: use skb_attempt_defer_free()"), but AFAICS this problem could happen with TCP as well if pmtu discovery is off. The relevant problem path for udp is: 1. netns emits fragmented packets 2. nf_defrag_v6_hook reassembles them (in output hook) 3. reassembled skb is tracked (skb owns nf_conn reference) 4. ip6_output refragments 5. refragmented packets also own nf_conn reference (ip6_fragment calls ip6_copy_metadata()) 6. on input path, nf_defrag_v6_hook skips defragmentation: the fragments already have skb->nf_conn attached 7. skbs are reassembled via ipv6_frag_rcv() 8. skb_consume_udp -> skb_attempt_defer_free() -> skb ends up in pcpu freelist, but still has nf_conn reference. Possible solutions: 1 let defrag engine drop nf_conn entry, OR 2 export kick_defer_list_purge() and call it from the conntrack netns exit callback, OR 3 add skb_has_frag_list() check to skb_attempt_defer_free() 2 & 3 also solve ip_defrag.sh hang but share same drawback: Such reassembled skbs, queued to socket, can prevent conntrack module removal until userspace has consumed the packet. While both tcp and udp stack do call nf_reset_ct() before placing skb on socket queue, that function doesn't iterate frag_list skbs. Therefore drop nf_conn entries when they are placed in defrag queue. Keep the nf_conn entry of the first (offset 0) skb so that reassembled skb retains nf_conn entry for sake of TX path. Note that fixes tag is incorrect; it points to the commit introducing the 'ip_defrag.sh reproducible problem': no need to backport this patch to every stable kernel. Reported-by: syzbot+4393c47753b7808dac7d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/693b0fa7.050a0220.4004e.040d.GAE@google.com/ Fixes: 6471658dc66c ("udp: use skb_attempt_defer_free()") Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260102140030.32367-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysnet: sock: fix hardened usercopy panic in sock_recv_errqueueWeiming Shi
skbuff_fclone_cache was created without defining a usercopy region, [1] unlike skbuff_head_cache which properly whitelists the cb[] field. [2] This causes a usercopy BUG() when CONFIG_HARDENED_USERCOPY is enabled and the kernel attempts to copy sk_buff.cb data to userspace via sock_recv_errqueue() -> put_cmsg(). The crash occurs when: 1. TCP allocates an skb using alloc_skb_fclone() (from skbuff_fclone_cache) [1] 2. The skb is cloned via skb_clone() using the pre-allocated fclone [3] 3. The cloned skb is queued to sk_error_queue for timestamp reporting 4. Userspace reads the error queue via recvmsg(MSG_ERRQUEUE) 5. sock_recv_errqueue() calls put_cmsg() to copy serr->ee from skb->cb [4] 6. __check_heap_object() fails because skbuff_fclone_cache has no usercopy whitelist [5] When cloned skbs allocated from skbuff_fclone_cache are used in the socket error queue, accessing the sock_exterr_skb structure in skb->cb via put_cmsg() triggers a usercopy hardening violation: [ 5.379589] usercopy: Kernel memory exposure attempt detected from SLUB object 'skbuff_fclone_cache' (offset 296, size 16)! [ 5.382796] kernel BUG at mm/usercopy.c:102! [ 5.383923] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI [ 5.384903] CPU: 1 UID: 0 PID: 138 Comm: poc_put_cmsg Not tainted 6.12.57 #7 [ 5.384903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 5.384903] RIP: 0010:usercopy_abort+0x6c/0x80 [ 5.384903] Code: 1a 86 51 48 c7 c2 40 15 1a 86 41 52 48 c7 c7 c0 15 1a 86 48 0f 45 d6 48 c7 c6 80 15 1a 86 48 89 c1 49 0f 45 f3 e8 84 27 88 ff <0f> 0b 490 [ 5.384903] RSP: 0018:ffffc900006f77a8 EFLAGS: 00010246 [ 5.384903] RAX: 000000000000006f RBX: ffff88800f0ad2a8 RCX: 1ffffffff0f72e74 [ 5.384903] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff87b973a0 [ 5.384903] RBP: 0000000000000010 R08: 0000000000000000 R09: fffffbfff0f72e74 [ 5.384903] R10: 0000000000000003 R11: 79706f6372657375 R12: 0000000000000001 [ 5.384903] R13: ffff88800f0ad2b8 R14: ffffea00003c2b40 R15: ffffea00003c2b00 [ 5.384903] FS: 0000000011bc4380(0000) GS:ffff8880bf100000(0000) knlGS:0000000000000000 [ 5.384903] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5.384903] CR2: 000056aa3b8e5fe4 CR3: 000000000ea26004 CR4: 0000000000770ef0 [ 5.384903] PKRU: 55555554 [ 5.384903] Call Trace: [ 5.384903] <TASK> [ 5.384903] __check_heap_object+0x9a/0xd0 [ 5.384903] __check_object_size+0x46c/0x690 [ 5.384903] put_cmsg+0x129/0x5e0 [ 5.384903] sock_recv_errqueue+0x22f/0x380 [ 5.384903] tls_sw_recvmsg+0x7ed/0x1960 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5.384903] ? schedule+0x6d/0x270 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5.384903] ? mutex_unlock+0x81/0xd0 [ 5.384903] ? __pfx_mutex_unlock+0x10/0x10 [ 5.384903] ? __pfx_tls_sw_recvmsg+0x10/0x10 [ 5.384903] ? _raw_spin_lock_irqsave+0x8f/0xf0 [ 5.384903] ? _raw_read_unlock_irqrestore+0x20/0x40 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 The crash offset 296 corresponds to skb2->cb within skbuff_fclones: - sizeof(struct sk_buff) = 232 - offsetof(struct sk_buff, cb) = 40 - offset of skb2.cb in fclones = 232 + 40 = 272 - crash offset 296 = 272 + 24 (inside sock_exterr_skb.ee) This patch uses a local stack variable as a bounce buffer to avoid the hardened usercopy check failure. [1] https://elixir.bootlin.com/linux/v6.12.62/source/net/ipv4/tcp.c#L885 [2] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5104 [3] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5566 [4] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5491 [5] https://elixir.bootlin.com/linux/v6.12.62/source/mm/slub.c#L5719 Fixes: 6d07d1cd300f ("usercopy: Restrict non-usercopy caches to size 0") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251223203534.1392218-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysinet: ping: Fix icmp out countingyuan.gao
When the ping program uses an IPPROTO_ICMP socket to send ICMP_ECHO messages, ICMP_MIB_OUTMSGS is counted twice. ping_v4_sendmsg ping_v4_push_pending_frames ip_push_pending_frames ip_finish_skb __ip_make_skb icmp_out_count(net, icmp_type); // first count icmp_out_count(sock_net(sk), user_icmph.type); // second count However, when the ping program uses an IPPROTO_RAW socket, ICMP_MIB_OUTMSGS is counted correctly only once. Therefore, the first count should be removed. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by: yuan.gao <yuan.gao@ucloud.cn> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20251224063145.3615282-1-yuan.gao@ucloud.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5 daysbridge: fix C-VLAN preservation in 802.1ad vlan_tunnel egressAlexandre Knecht
When using an 802.1ad bridge with vlan_tunnel, the C-VLAN tag is incorrectly stripped from frames during egress processing. br_handle_egress_vlan_tunnel() uses skb_vlan_pop() to remove the S-VLAN from hwaccel before VXLAN encapsulation. However, skb_vlan_pop() also moves any "next" VLAN from the payload into hwaccel: /* move next vlan tag to hw accel tag */ __skb_vlan_pop(skb, &vlan_tci); __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci); For QinQ frames where the C-VLAN sits in the payload, this moves it to hwaccel where it gets lost during VXLAN encapsulation. Fix by calling __vlan_hwaccel_clear_tag() directly, which clears only the hwaccel S-VLAN and leaves the payload untouched. This path is only taken when vlan_tunnel is enabled and tunnel_info is configured, so 802.1Q bridges are unaffected. Tested with 802.1ad bridge + VXLAN vlan_tunnel, verified C-VLAN preserved in VXLAN payload via tcpdump. Fixes: 11538d039ac6 ("bridge: vlan dst_metadata hooks in ingress and egress paths") Signed-off-by: Alexandre Knecht <knecht.alexandre@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20251228020057.2788865-1-knecht.alexandre@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
7 daysnetfilter: nf_conncount: update last_gc only when GC has been performedFernando Fernandez Mancera
Currently last_gc is being updated everytime a new connection is tracked, that means that it is updated even if a GC wasn't performed. With a sufficiently high packet rate, it is possible to always bypass the GC, causing the list to grow infinitely. Update the last_gc value only when a GC has been actually performed. Fixes: d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Florian Westphal <fw@strlen.de>
7 daysnetfilter: nf_tables: fix memory leak in nf_tables_newrule()Zilin Guan
In nf_tables_newrule(), if nft_use_inc() fails, the function jumps to the err_release_rule label without freeing the allocated flow, leading to a memory leak. Fix this by adding a new label err_destroy_flow and jumping to it when nft_use_inc() fails. This ensures that the flow is properly released in this error case. Fixes: 1689f25924ada ("netfilter: nf_tables: report use refcount overflow") Signed-off-by: Zilin Guan <zilin@seu.edu.cn> Signed-off-by: Florian Westphal <fw@strlen.de>
8 daysnetfilter: replace -EEXIST with -EBUSYDaniel Gomez
The -EEXIST error code is reserved by the module loading infrastructure to indicate that a module is already loaded. When a module's init function returns -EEXIST, userspace tools like kmod interpret this as "module already loaded" and treat the operation as successful, returning 0 to the user even though the module initialization actually failed. Replace -EEXIST with -EBUSY to ensure correct error reporting in the module initialization path. Affected modules: * ebtable_broute ebtable_filter ebtable_nat arptable_filter * ip6table_filter ip6table_mangle ip6table_nat ip6table_raw * ip6table_security iptable_filter iptable_mangle iptable_nat * iptable_raw iptable_security Signed-off-by: Daniel Gomez <da.gomez@samsung.com> Signed-off-by: Florian Westphal <fw@strlen.de>
8 daysnetfilter: nft_synproxy: avoid possible data-race on update operationFernando Fernandez Mancera
During nft_synproxy eval we are reading nf_synproxy_info struct which can be modified on update operation concurrently. As nf_synproxy_info struct fits in 32 bits, use READ_ONCE/WRITE_ONCE annotations. Fixes: ee394f96ad75 ("netfilter: nft_synproxy: add synproxy stateful object support") Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Florian Westphal <fw@strlen.de>
8 daysnetfilter: nft_set_pipapo: fix range overlap detectionFlorian Westphal
set->klen has to be used, not sizeof(). The latter only compares a single register but a full check of the entire key is needed. Example: table ip t { map s { typeof iifname . ip saddr : verdict flags interval } } nft add element t s '{ "lo" . 10.0.0.0/24 : drop }' # no error, expected nft add element t s '{ "lo" . 10.0.0.0/24 : drop }' # no error, expected nft add element t s '{ "lo" . 10.0.0.0/8 : drop }' # bug: no error The 3rd 'add element' should be rejected via -ENOTEMPTY, not -EEXIST, so userspace / nft can report an error to the user. The latter is only correct for the 2nd case (re-add of existing element). As-is, userspace is told that the command was successful, but no elements were added. After this patch, 3rd command gives: Error: Could not process rule: File exists add element t s { "lo" . 127.0.0.0/8 . "lo" : drop } ^^^^^^^^^^^^^^^^^^^^^^^^^ Fixes: 0eb4b5ee33f2 ("netfilter: nft_set_pipapo: Separate partial and complete overlap cases on insertion") Signed-off-by: Florian Westphal <fw@strlen.de>
10 daysMerge tag 'net-6.19-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from Bluetooth and WiFi. Notably this includes the fix for the iwlwifi issue you reported. Current release - regressions: - core: avoid prefetching NULL pointers - wifi: - iwlwifi: implement settime64 as stub for MVM/MLD PTP - mac80211: fix list iteration in ieee80211_add_virtual_monitor() - handshake: fix null-ptr-deref in handshake_complete() - eth: mana: fix use-after-free in reset service rescan path Previous releases - regressions: - openvswitch: avoid needlessly taking the RTNL on vport destroy - dsa: properly keep track of conduit reference - ipv4: - fix error route reference count leak with nexthop objects - fib: restore ECMP balance from loopback - mptcp: ensure context reset on disconnect() - bluetooth: fix potential UaF in btusb - nfc: fix deadlock between nfc_unregister_device and rfkill_fop_write - eth: - gve: defer interrupt enabling until NAPI registration - i40e: fix scheduling in set_rx_mode - macb: relocate mog_init_rings() callback from macb_mac_link_up() to macb_open() - rtl8150: fix memory leak on usb_submit_urb() failure - wifi: 8192cu: fix tid out of range in rtl92cu_tx_fill_desc() Previous releases - always broken: - ip6_gre: make ip6gre_header() robust - ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT - af_unix: don't post cmsg for SO_INQ unless explicitly asked for - phy: mediatek: fix nvmem cell reference leak in mt798x_phy_calibration - wifi: mac80211: discard beacon frames to non-broadcast address - eth: - iavf: fix off-by-one issues in iavf_config_rss_reg() - stmmac: fix the crash issue for zero copy XDP_TX action - team: fix check for port enabled when priority changes" * tag 'net-6.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (64 commits) ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT net: rose: fix invalid array index in rose_kill_by_device() net: enetc: do not print error log if addr is 0 net: macb: Relocate mog_init_rings() callback from macb_mac_link_up() to macb_open() selftests: fib_test: Add test case for ipv4 multi nexthops net: fib: restore ECMP balance from loopback selftests: fib_nexthops: Add test cases for error routes deletion ipv4: Fix reference count leak when using error routes with nexthop objects net: usb: sr9700: fix incorrect command used to write single register ipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr() usbnet: avoid a possible crash in dql_completed() gve: defer interrupt enabling until NAPI registration net: stmmac: fix the crash issue for zero copy XDP_TX action octeontx2-pf: fix "UBSAN: shift-out-of-bounds error" af_unix: don't post cmsg for SO_INQ unless explicitly asked for net: mana: Fix use-after-free in reset service rescan path net: avoid prefetching NULL pointers net: bridge: Describe @tunnel_hash member in net_bridge_vlan_group struct net: nfc: fix deadlock between nfc_unregister_device and rfkill_fop_write net: usb: asix: validate PHY address before use ...
10 daysipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RTJiayuan Chen
On PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the current task can be preempted. Another task running on the same CPU may then execute rt6_make_pcpu_route() and successfully install a pcpu_rt entry. When the first task resumes execution, its cmpxchg() in rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer NULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding mdelay() after rt6_get_pcpu_route(). Using preempt_disable/enable is not appropriate here because ip6_rt_pcpu_alloc() may sleep. Fix this by handling the cmpxchg() failure gracefully on PREEMPT_RT: free our allocation and return the existing pcpu_rt installed by another task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT kernels where such races should not occur. Link: https://syzkaller.appspot.com/bug?extid=9b35e9bc0951140d13e6 Fixes: d2d6422f8bd1 ("x86: Allow to enable PREEMPT_RT.") Reported-by: syzbot+9b35e9bc0951140d13e6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6918cd88.050a0220.1c914e.0045.GAE@google.com/T/ Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Link: https://patch.msgid.link/20251223051413.124687-1-jiayuan.chen@linux.dev Signed-off-by: Paolo Abeni <pabeni@redhat.com>
10 daysnet: rose: fix invalid array index in rose_kill_by_device()Pwnverse
rose_kill_by_device() collects sockets into a local array[] and then iterates over them to disconnect sockets bound to a device being brought down. The loop mistakenly indexes array[cnt] instead of array[i]. For cnt < ARRAY_SIZE(array), this reads an uninitialized entry; for cnt == ARRAY_SIZE(array), it is an out-of-bounds read. Either case can lead to an invalid socket pointer dereference and also leaks references taken via sock_hold(). Fix the index to use i. Fixes: 64b8bc7d5f143 ("net/rose: fix races in rose_kill_by_device()") Co-developed-by: Fatma Alwasmi <falwasmi@purdue.edu> Signed-off-by: Fatma Alwasmi <falwasmi@purdue.edu> Signed-off-by: Pwnverse <stanksal@purdue.edu> Link: https://patch.msgid.link/20251222212227.4116041-1-ritviktanksalkar@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
10 daysnet: fib: restore ECMP balance from loopbackVadim Fedorenko
Preference of nexthop with source address broke ECMP for packets with source addresses which are not in the broadcast domain, but rather added to loopback/dummy interfaces. Original behaviour was to balance over nexthops while now it uses the latest nexthop from the group. To fix the issue introduce next hop scoring system where next hops with source address equal to requested will always have higher priority. For the case with 198.51.100.1/32 assigned to dummy0 and routed using 192.0.2.0/24 and 203.0.113.0/24 networks: 2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 link/ether d6:54:8a:ff:78:f5 brd ff:ff:ff:ff:ff:ff inet 198.51.100.1/32 scope global dummy0 valid_lft forever preferred_lft forever 7: veth1@if6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 06:ed:98:87:6d:8a brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet 192.0.2.2/24 scope global veth1 valid_lft forever preferred_lft forever inet6 fe80::4ed:98ff:fe87:6d8a/64 scope link proto kernel_ll valid_lft forever preferred_lft forever 9: veth3@if8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether ae:75:23:38:a0:d2 brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet 203.0.113.2/24 scope global veth3 valid_lft forever preferred_lft forever inet6 fe80::ac75:23ff:fe38:a0d2/64 scope link proto kernel_ll valid_lft forever preferred_lft forever ~ ip ro list: default nexthop via 192.0.2.1 dev veth1 weight 1 nexthop via 203.0.113.1 dev veth3 weight 1 192.0.2.0/24 dev veth1 proto kernel scope link src 192.0.2.2 203.0.113.0/24 dev veth3 proto kernel scope link src 203.0.113.2 before: for i in {1..255} ; do ip ro get 10.0.0.$i; done | grep veth | awk ' {print $(NF-2)}' | sort | uniq -c: 255 veth3 after: for i in {1..255} ; do ip ro get 10.0.0.$i; done | grep veth | awk ' {print $(NF-2)}' | sort | uniq -c: 122 veth1 133 veth3 Fixes: 32607a332cfe ("ipv4: prefer multipath nexthop that matches source address") Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20251221192639.3911901-1-vadim.fedorenko@linux.dev Signed-off-by: Paolo Abeni <pabeni@redhat.com>
10 daysipv4: Fix reference count leak when using error routes with nexthop objectsIdo Schimmel
When a nexthop object is deleted, it is marked as dead and then fib_table_flush() is called to flush all the routes that are using the dead nexthop. The current logic in fib_table_flush() is to only flush error routes (e.g., blackhole) when it is called as part of network namespace dismantle (i.e., with flush_all=true). Therefore, error routes are not flushed when their nexthop object is deleted: # ip link add name dummy1 up type dummy # ip nexthop add id 1 dev dummy1 # ip route add 198.51.100.1/32 nhid 1 # ip route add blackhole 198.51.100.2/32 nhid 1 # ip nexthop del id 1 # ip route show blackhole 198.51.100.2 nhid 1 dev dummy1 As such, they keep holding a reference on the nexthop object which in turn holds a reference on the nexthop device, resulting in a reference count leak: # ip link del dev dummy1 [ 70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2 Fix by flushing error routes when their nexthop is marked as dead. IPv6 does not suffer from this problem. Fixes: 493ced1ac47c ("ipv4: Allow routes to use nexthop objects") Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Closes: https://lore.kernel.org/netdev/d943f806-4da6-4970-ac28-b9373b0e63ac@I-love.SAKURA.ne.jp/ Reported-by: syzbot+881d65229ca4f9ae8c84@syzkaller.appspotmail.com Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20251221144829.197694-1-idosch@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
11 daysipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr()Will Rosenberg
There exists a kernel oops caused by a BUG_ON(nhead < 0) at net/core/skbuff.c:2232 in pskb_expand_head(). This bug is triggered as part of the calipso_skbuff_setattr() routine when skb_cow() is passed headroom > INT_MAX (i.e. (int)(skb_headroom(skb) + len_delta) < 0). The root cause of the bug is due to an implicit integer cast in __skb_cow(). The check (headroom > skb_headroom(skb)) is meant to ensure that delta = headroom - skb_headroom(skb) is never negative, otherwise we will trigger a BUG_ON in pskb_expand_head(). However, if headroom > INT_MAX and delta <= -NET_SKB_PAD, the check passes, delta becomes negative, and pskb_expand_head() is passed a negative value for nhead. Fix the trigger condition in calipso_skbuff_setattr(). Avoid passing "negative" headroom sizes to skb_cow() within calipso_skbuff_setattr() by only using skb_cow() to grow headroom. PoC: Using `netlabelctl` tool: netlabelctl map del default netlabelctl calipso add pass doi:7 netlabelctl map add default address:0::1/128 protocol:calipso,7 Then run the following PoC: int fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); // setup msghdr int cmsg_size = 2; int cmsg_len = 0x60; struct msghdr msg; struct sockaddr_in6 dest_addr; struct cmsghdr * cmsg = (struct cmsghdr *) calloc(1, sizeof(struct cmsghdr) + cmsg_len); msg.msg_name = &dest_addr; msg.msg_namelen = sizeof(dest_addr); msg.msg_iov = NULL; msg.msg_iovlen = 0; msg.msg_control = cmsg; msg.msg_controllen = cmsg_len; msg.msg_flags = 0; // setup sockaddr dest_addr.sin6_family = AF_INET6; dest_addr.sin6_port = htons(31337); dest_addr.sin6_flowinfo = htonl(31337); dest_addr.sin6_addr = in6addr_loopback; dest_addr.sin6_scope_id = 31337; // setup cmsghdr cmsg->cmsg_len = cmsg_len; cmsg->cmsg_level = IPPROTO_IPV6; cmsg->cmsg_type = IPV6_HOPOPTS; char * hop_hdr = (char *)cmsg + sizeof(struct cmsghdr); hop_hdr[1] = 0x9; //set hop size - (0x9 + 1) * 8 = 80 sendmsg(fd, &msg, 0); Fixes: 2917f57b6bc1 ("calipso: Allow the lsm to label the skbuff directly.") Suggested-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Will Rosenberg <whrosenb@asu.edu> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://patch.msgid.link/20251219173637.797418-1-whrosenb@asu.edu Signed-off-by: Paolo Abeni <pabeni@redhat.com>
11 daysMerge tag 'wireless-2025-12-17' of ↵Paolo Abeni
https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless Johannes Berg says: ==================== Various fixes all over, most are recent regressions but also some long-standing issues: - cfg80211: - fix an issue with overly long SSIDs - mac80211: - long-standing beacon protection issue on some devices - for for a multi-BSSID AP-side issue - fix a syzbot warning on OCB (not really used in practice) - remove WARN on connections using disabled channels, as that can happen due to changes in the disable flag - fix monitor mode list iteration - iwlwifi: - fix firmware loading on certain (really old) devices - add settime64 to PTP clock to avoid a warning and clock registration failure, but it's not actually supported - rtw88: - remove WQ_UNBOUND since it broke USB adapters (because it can't be used with WQ_BH) - fix SDIO issues with certain devices - rtl8192cu: fix TID array out-of-bounds (since 6.9) - wlcore (TI): add missing skb push headroom increase * tag 'wireless-2025-12-17' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless: wifi: iwlwifi: Implement settime64 as stub for MVM/MLD PTP wifi: iwlwifi: Fix firmware version handling wifi: mac80211: ocb: skip rx_no_sta when interface is not joined wifi: mac80211: do not use old MBSSID elements wifi: mac80211: don't WARN for connections on invalid channels wifi: wlcore: ensure skb headroom before skb_push wifi: cfg80211: sme: store capped length in __cfg80211_connect_result() wifi: mac80211: fix list iteration in ieee80211_add_virtual_monitor() wifi: mac80211: Discard Beacon frames to non-broadcast address Revert "wifi: rtw88: add WQ_UNBOUND to alloc_workqueue users" wifi: rtlwifi: 8192cu: fix tid out of range in rtl92cu_tx_fill_desc() wifi: rtw88: limit indirect IO under powered off for RTL8822CS ==================== Link: https://patch.msgid.link/20251217201441.59876-3-johannes@sipsolutions.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
12 daysaf_unix: don't post cmsg for SO_INQ unless explicitly asked forJens Axboe
A previous commit added SO_INQ support for AF_UNIX (SOCK_STREAM), but it posts a SCM_INQ cmsg even if just msg->msg_get_inq is set. This is incorrect, as ->msg_get_inq is just the caller asking for the remainder to be passed back in msg->msg_inq, it has nothing to do with cmsg. The original commit states that this is done to make sockets io_uring-friendly", but it's actually incorrect as io_uring doesn't use cmsg headers internally at all, and it's actively wrong as this means that cmsg's are always posted if someone does recvmsg via io_uring. Fix that up by only posting a cmsg if u->recvmsg_inq is set. Additionally, mirror how TCP handles inquiry handling in that it should only be done for a successful return. This makes the logic for the two identical. Cc: stable@vger.kernel.org Fixes: df30285b3670 ("af_unix: Introduce SO_INQ.") Reported-by: Julian Orth <ju.orth@gmail.com> Link: https://github.com/axboe/liburing/issues/1509 Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/07adc0c2-2c3b-4d08-8af1-1c466a40b6a8@kernel.dk Signed-off-by: Paolo Abeni <pabeni@redhat.com>
12 daysnet: avoid prefetching NULL pointersEric Dumazet
Aditya Gupta reported PowerPC crashes bisected to the blamed commit. Apparently some platforms do not allow prefetch() on arbitrary pointers. prefetch(next); prefetch(&next->priority); // CRASH when next == NULL Only NULL seems to be supported, with specific handling in prefetch(). Add a conditional to avoid the two prefetches and the skb->next clearing for the last skb in the list. Fixes: b2e9821cff6c ("net: prefech skb->priority in __dev_xmit_skb()") Reported-by: Aditya Gupta <adityag@linux.ibm.com> Closes: https://lore.kernel.org/netdev/e9f4abee-b132-440f-a50e-bced0868b5a7@linux.ibm.com/T/#mddc372b64ec5a3b181acc9ee3909110c391cc18a Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Aditya Gupta <adityag@linux.ibm.com> Link: https://patch.msgid.link/20251218081844.809008-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
12 daysnet: bridge: Describe @tunnel_hash member in net_bridge_vlan_group structBagas Sanjaya
Sphinx reports kernel-doc warning: WARNING: ./net/bridge/br_private.h:267 struct member 'tunnel_hash' not described in 'net_bridge_vlan_group' Fix it by describing @tunnel_hash member. Fixes: efa5356b0d9753 ("bridge: per vlan dst_metadata netlink support") Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20251218042936.24175-2-bagasdotme@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
12 daysnet: nfc: fix deadlock between nfc_unregister_device and rfkill_fop_writeDeepanshu Kartikey
A deadlock can occur between nfc_unregister_device() and rfkill_fop_write() due to lock ordering inversion between device_lock and rfkill_global_mutex. The problematic lock order is: Thread A (rfkill_fop_write): rfkill_fop_write() mutex_lock(&rfkill_global_mutex) rfkill_set_block() nfc_rfkill_set_block() nfc_dev_down() device_lock(&dev->dev) <- waits for device_lock Thread B (nfc_unregister_device): nfc_unregister_device() device_lock(&dev->dev) rfkill_unregister() mutex_lock(&rfkill_global_mutex) <- waits for rfkill_global_mutex This creates a classic ABBA deadlock scenario. Fix this by moving rfkill_unregister() and rfkill_destroy() outside the device_lock critical section. Store the rfkill pointer in a local variable before releasing the lock, then call rfkill_unregister() after releasing device_lock. This change is safe because rfkill_fop_write() holds rfkill_global_mutex while calling the rfkill callbacks, and rfkill_unregister() also acquires rfkill_global_mutex before cleanup. Therefore, rfkill_unregister() will wait for any ongoing callback to complete before proceeding, and device_del() is only called after rfkill_unregister() returns, preventing any use-after-free. The similar lock ordering in nfc_register_device() (device_lock -> rfkill_global_mutex via rfkill_register) is safe because during registration the device is not yet in rfkill_list, so no concurrent rfkill operations can occur on this device. Fixes: 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device") Cc: stable@vger.kernel.org Reported-by: syzbot+4ef89409a235d804c6c2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4ef89409a235d804c6c2 Link: https://lore.kernel.org/all/20251217054908.178907-1-kartikey406@gmail.com/T/ [v1] Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com> Link: https://patch.msgid.link/20251218012355.279940-1-kartikey406@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-24Merge tag 'nfsd-6.19-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: "A set of NFSD fixes that arrived just a bit late for the 6.19 merge window. Regression fixes: - Mark variable __maybe_unused to avoid W=1 build break Stable fixes: - NFSv4 file creation neglects setting ACL - Clear TIME_DELEG in the suppattr_exclcreat bitmap - Clear SECLABEL in the suppattr_exclcreat bitmap - Fix memory leak in nfsd_create_serv error paths - Bound check rq_pages index in inline path - Return 0 on success from svc_rdma_copy_inline_range - Use rc_pageoff for memcpy byte offset - Avoid NULL deref on zero length gss_token in gss_read_proxy_verf" * tag 'nfsd-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: NFSD: NFSv4 file creation neglects setting ACL NFSD: Clear TIME_DELEG in the suppattr_exclcreat bitmap NFSD: Clear SECLABEL in the suppattr_exclcreat bitmap nfsd: fix memory leak in nfsd_create_serv error paths nfsd: Mark variable __maybe_unused to avoid W=1 build break svcrdma: bound check rq_pages index in inline path svcrdma: return 0 on success from svc_rdma_copy_inline_range svcrdma: use rc_pageoff for memcpy byte offset SUNRPC: svcauth_gss: avoid NULL deref on zero length gss_token in gss_read_proxy_verf
2025-12-23Merge tag 'for-net-2025-12-19' of ↵Paolo Abeni
git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth Luiz Augusto von Dentz says: ==================== bluetooth pull request for net: - MGMT: report BIS capability flags in supported settings - btusb: revert use of devm_kzalloc in btusb * tag 'for-net-2025-12-19' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth: Bluetooth: btusb: revert use of devm_kzalloc in btusb Bluetooth: MGMT: report BIS capability flags in supported settings ==================== Link: https://patch.msgid.link/20251219223118.90141-1-luiz.dentz@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-23net: dsa: fix missing put_device() in dsa_tree_find_first_conduit()Vladimir Oltean
of_find_net_device_by_node() searches net devices by their /sys/class/net/, entry. It is documented in its kernel-doc that: * If successful, returns a pointer to the net_device with the embedded * struct device refcount incremented by one, or NULL on failure. The * refcount must be dropped when done with the net_device. We are missing a put_device(&conduit->dev) which we could place at the end of dsa_tree_find_first_conduit(). But to explain why calling put_device() right away is safe is the same as to explain why the chosen solution is different. The code is very poorly split: dsa_tree_find_first_conduit() was first introduced in commit 95f510d0b792 ("net: dsa: allow the DSA master to be seen and changed through rtnetlink") but was first used several commits later, in commit acc43b7bf52a ("net: dsa: allow masters to join a LAG"). Assume there is a switch with 2 CPU ports and 2 conduits, eno2 and eno3. When we create a LAG (bonding or team device) and place eno2 and eno3 beneath it, we create a 3rd conduit (the LAG device itself), but this is slightly different than the first two. Namely, the cpu_dp->conduit pointer of the CPU ports does not change, and remains pointing towards the physical Ethernet controllers which are now LAG ports. Only 2 things change: - the LAG device has a dev->dsa_ptr which marks it as a DSA conduit - dsa_port_to_conduit(user port) finds the LAG and not the physical conduit, because of the dp->cpu_port_in_lag bit being set. When the LAG device is destroyed, dsa_tree_migrate_ports_from_lag_conduit() is called and this is where dsa_tree_find_first_conduit() kicks in. This is the logical mistake and the reason why introducing code in one patch and using it from another is bad practice. I didn't realize that I don't have to call of_find_net_device_by_node() again; the cpu_dp->conduit association was never undone, and is still available for direct (re)use. There's only one concern - maybe the conduit disappeared in the meantime, but the netdev_hold() call we made during dsa_port_parse_cpu() (see previous change) ensures that this was not the case. Therefore, fixing the code means reimplementing it in the simplest way. I am blaming the time of use, since this is what "git blame" would show if we were to monitor for the conduit's kobject's refcount remaining elevated instead of being freed. Tested on the NXP LS1028A, using the steps from Documentation/networking/dsa/configuration.rst section "Affinity of user ports to CPU ports", followed by (extra prints added by me): $ ip link del bond0 mscc_felix 0000:00:00.5 swp3: Link is Down bond0 (unregistering): (slave eno2): Releasing backup interface fsl_enetc 0000:00:00.2 eno2: Link is Down mscc_felix 0000:00:00.5 swp0: bond0 disappeared, migrating to eno2 mscc_felix 0000:00:00.5 swp1: bond0 disappeared, migrating to eno2 mscc_felix 0000:00:00.5 swp2: bond0 disappeared, migrating to eno2 mscc_felix 0000:00:00.5 swp3: bond0 disappeared, migrating to eno2 Fixes: acc43b7bf52a ("net: dsa: allow masters to join a LAG") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://patch.msgid.link/20251215150236.3931670-2-vladimir.oltean@nxp.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-23net: dsa: properly keep track of conduit referenceVladimir Oltean
Problem description ------------------- DSA has a mumbo-jumbo of reference handling of the conduit net device and its kobject which, sadly, is just wrong and doesn't make sense. There are two distinct problems. 1. The OF path, which uses of_find_net_device_by_node(), never releases the elevated refcount on the conduit's kobject. Nominally, the OF and non-OF paths should result in objects having identical reference counts taken, and it is already suspicious that dsa_dev_to_net_device() has a put_device() call which is missing in dsa_port_parse_of(), but we can actually even verify that an issue exists. With CONFIG_DEBUG_KOBJECT_RELEASE=y, if we run this command "before" and "after" applying this patch: (unbind the conduit driver for net device eno2) echo 0000:00:00.2 > /sys/bus/pci/drivers/fsl_enetc/unbind we see these lines in the output diff which appear only with the patch applied: kobject: 'eno2' (ffff002009a3a6b8): kobject_release, parent 0000000000000000 (delayed 1000) kobject: '109' (ffff0020099d59a0): kobject_release, parent 0000000000000000 (delayed 1000) 2. After we find the conduit interface one way (OF) or another (non-OF), it can get unregistered at any time, and DSA remains with a long-lived, but in this case stale, cpu_dp->conduit pointer. Holding the net device's underlying kobject isn't actually of much help, it just prevents it from being freed (but we never need that kobject directly). What helps us to prevent the net device from being unregistered is the parallel netdev reference mechanism (dev_hold() and dev_put()). Actually we actually use that netdev tracker mechanism implicitly on user ports since commit 2f1e8ea726e9 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings"), via netdev_upper_dev_link(). But time still passes at DSA switch probe time between the initial of_find_net_device_by_node() code and the user port creation time, time during which the conduit could unregister itself and DSA wouldn't know about it. So we have to run of_find_net_device_by_node() under rtnl_lock() to prevent that from happening, and release the lock only with the netdev tracker having acquired the reference. Do we need to keep the reference until dsa_unregister_switch() / dsa_switch_shutdown()? 1: Maybe yes. A switch device will still be registered even if all user ports failed to probe, see commit 86f8b1c01a0a ("net: dsa: Do not make user port errors fatal"), and the cpu_dp->conduit pointers remain valid. I haven't audited all call paths to see whether they will actually use the conduit in lack of any user port, but if they do, it seems safer to not rely on user ports for that reference. 2. Definitely yes. We support changing the conduit which a user port is associated to, and we can get into a situation where we've moved all user ports away from a conduit, thus no longer hold any reference to it via the net device tracker. But we shouldn't let it go nonetheless - see the next change in relation to dsa_tree_find_first_conduit() and LAG conduits which disappear. We have to be prepared to return to the physical conduit, so the CPU port must explicitly keep another reference to it. This is also to say: the user ports and their CPU ports may not always keep a reference to the same conduit net device, and both are needed. As for the conduit's kobject for the /sys/class/net/ entry, we don't care about it, we can release it as soon as we hold the net device object itself. History and blame attribution ----------------------------- The code has been refactored so many times, it is very difficult to follow and properly attribute a blame, but I'll try to make a short history which I hope to be correct. We have two distinct probing paths: - one for OF, introduced in 2016 in commit 83c0afaec7b7 ("net: dsa: Add new binding implementation") - one for non-OF, introduced in 2017 in commit 71e0bbde0d88 ("net: dsa: Add support for platform data") These are both complete rewrites of the original probing paths (which used struct dsa_switch_driver and other weird stuff, instead of regular devices on their respective buses for register access, like MDIO, SPI, I2C etc): - one for OF, introduced in 2013 in commit 5e95329b701c ("dsa: add device tree bindings to register DSA switches") - one for non-OF, introduced in 2008 in commit 91da11f870f0 ("net: Distributed Switch Architecture protocol support") except for tiny bits and pieces like dsa_dev_to_net_device() which were seemingly carried over since the original commit, and used to this day. The point is that the original probing paths received a fix in 2015 in the form of commit 679fb46c5785 ("net: dsa: Add missing master netdev dev_put() calls"), but the fix never made it into the "new" (dsa2) probing paths that can still be traced to today, and the fixed probing path was later deleted in 2019 in commit 93e86b3bc842 ("net: dsa: Remove legacy probing support"). That is to say, the new probing paths were never quite correct in this area. The existence of the legacy probing support which was deleted in 2019 explains why dsa_dev_to_net_device() returns a conduit with elevated refcount (because it was supposed to be released during dsa_remove_dst()). After the removal of the legacy code, the only user of dsa_dev_to_net_device() calls dev_put(conduit) immediately after this function returns. This pattern makes no sense today, and can only be interpreted historically to understand why dev_hold() was there in the first place. Change details -------------- Today we have a better netdev tracking infrastructure which we should use. Logically netdev_hold() belongs in common code (dsa_port_parse_cpu(), where dp->conduit is assigned), but there is a tradeoff to be made with the rtnl_lock() section which would become a bit too long if we did that - dsa_port_parse_cpu() also calls request_module(). So we duplicate a bit of logic in order for the callers of dsa_port_parse_cpu() to be the ones responsible of holding the conduit reference and releasing it on error. This shortens the rtnl_lock() section significantly. In the dsa_switch_probe() error path, dsa_switch_release_ports() will be called in a number of situations, one being where dsa_port_parse_cpu() maybe didn't get the chance to run at all (a different port failed earlier, etc). So we have to test for the conduit being NULL prior to calling netdev_put(). There have still been so many transformations to the code since the blamed commits (rename master -> conduit, commit 0650bf52b31f ("net: dsa: be compatible with masters which unregister on shutdown")), that it only makes sense to fix the code using the best methods available today and see how it can be backported to stable later. I suspect the fix cannot even be backported to kernels which lack dsa_switch_shutdown(), and I suspect this is also maybe why the long-lived conduit reference didn't make it into the new DSA probing paths at the time (problems during shutdown). Because dsa_dev_to_net_device() has a single call site and has to be changed anyway, the logic was just absorbed into the non-OF dsa_port_parse(). Tested on the ocelot/felix switch and on dsa_loop, both on the NXP LS1028A with CONFIG_DEBUG_KOBJECT_RELEASE=y. Reported-by: Ma Ke <make24@iscas.ac.cn> Closes: https://lore.kernel.org/netdev/20251214131204.4684-1-make24@iscas.ac.cn/ Fixes: 83c0afaec7b7 ("net: dsa: Add new binding implementation") Fixes: 71e0bbde0d88 ("net: dsa: Add support for platform data") Reviewed-by: Jonas Gorski <jonas.gorski@gmail.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://patch.msgid.link/20251215150236.3931670-1-vladimir.oltean@nxp.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-23erspan: Initialize options_len before referencing options.Frode Nordahl
The struct ip_tunnel_info has a flexible array member named options that is protected by a counted_by(options_len) attribute. The compiler will use this information to enforce runtime bounds checking deployed by FORTIFY_SOURCE string helpers. As laid out in the GCC documentation, the counter must be initialized before the first reference to the flexible array member. After scanning through the files that use struct ip_tunnel_info and also refer to options or options_len, it appears the normal case is to use the ip_tunnel_info_opts_set() helper. Said helper would initialize options_len properly before copying data into options, however in the GRE ERSPAN code a partial update is done, preventing the use of the helper function. Before this change the handling of ERSPAN traffic in GRE tunnels would cause a kernel panic when the kernel is compiled with GCC 15+ and having FORTIFY_SOURCE configured: memcpy: detected buffer overflow: 4 byte write of buffer size 0 Call Trace: <IRQ> __fortify_panic+0xd/0xf erspan_rcv.cold+0x68/0x83 ? ip_route_input_slow+0x816/0x9d0 gre_rcv+0x1b2/0x1c0 gre_rcv+0x8e/0x100 ? raw_v4_input+0x2a0/0x2b0 ip_protocol_deliver_rcu+0x1ea/0x210 ip_local_deliver_finish+0x86/0x110 ip_local_deliver+0x65/0x110 ? ip_rcv_finish_core+0xd6/0x360 ip_rcv+0x186/0x1a0 Cc: stable@vger.kernel.org Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-counted_005fby-variable-attribute Reported-at: https://launchpad.net/bugs/2129580 Fixes: bb5e62f2d547 ("net: Add options as a flexible array to struct ip_tunnel_info") Signed-off-by: Frode Nordahl <fnordahl@ubuntu.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20251213101338.4693-1-fnordahl@ubuntu.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-23mptcp: ensure context reset on disconnect()Paolo Abeni
After the blamed commit below, if the MPC subflow is already in TCP_CLOSE status or has fallback to TCP at mptcp_disconnect() time, mptcp_do_fastclose() skips setting the `send_fastclose flag` and the later __mptcp_close_ssk() does not reset anymore the related subflow context. Any later connection will be created with both the `request_mptcp` flag and the msk-level fallback status off (it is unconditionally cleared at MPTCP disconnect time), leading to a warning in subflow_data_ready(): WARNING: CPU: 26 PID: 8996 at net/mptcp/subflow.c:1519 subflow_data_ready (net/mptcp/subflow.c:1519 (discriminator 13)) Modules linked in: CPU: 26 UID: 0 PID: 8996 Comm: syz.22.39 Not tainted 6.18.0-rc7-05427-g11fc074f6c36 #1 PREEMPT(voluntary) Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 RIP: 0010:subflow_data_ready (net/mptcp/subflow.c:1519 (discriminator 13)) Code: 90 0f 0b 90 90 e9 04 fe ff ff e8 b7 1e f5 fe 89 ee bf 07 00 00 00 e8 db 19 f5 fe 83 fd 07 0f 84 35 ff ff ff e8 9d 1e f5 fe 90 <0f> 0b 90 e9 27 ff ff ff e8 8f 1e f5 fe 4c 89 e7 48 89 de e8 14 09 RSP: 0018:ffffc9002646fb30 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88813b218000 RCX: ffffffff825c8435 RDX: ffff8881300b3580 RSI: ffffffff825c8443 RDI: 0000000000000005 RBP: 000000000000000b R08: ffffffff825c8435 R09: 000000000000000b R10: 0000000000000005 R11: 0000000000000007 R12: ffff888131ac0000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f88330af6c0(0000) GS:ffff888a93dd2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f88330aefe8 CR3: 000000010ff59000 CR4: 0000000000350ef0 Call Trace: <TASK> tcp_data_ready (net/ipv4/tcp_input.c:5356) tcp_data_queue (net/ipv4/tcp_input.c:5445) tcp_rcv_state_process (net/ipv4/tcp_input.c:7165) tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1955) __release_sock (include/net/sock.h:1158 (discriminator 6) net/core/sock.c:3180 (discriminator 6)) release_sock (net/core/sock.c:3737) mptcp_sendmsg (net/mptcp/protocol.c:1763 net/mptcp/protocol.c:1857) inet_sendmsg (net/ipv4/af_inet.c:853 (discriminator 7)) __sys_sendto (net/socket.c:727 (discriminator 15) net/socket.c:742 (discriminator 15) net/socket.c:2244 (discriminator 15)) __x64_sys_sendto (net/socket.c:2247) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f883326702d Address the issue setting an explicit `fastclosing` flag at fastclose time, and checking such flag after mptcp_do_fastclose(). Fixes: ae155060247b ("mptcp: fix duplicate reset on fastclose") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20251212-net-mptcp-subflow_data_ready-warn-v1-2-d1f9fd1c36c8@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-23mptcp: fallback earlier on simult connectionPaolo Abeni
Syzkaller reports a simult-connect race leading to inconsistent fallback status: WARNING: CPU: 3 PID: 33 at net/mptcp/subflow.c:1515 subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1515 Modules linked in: CPU: 3 UID: 0 PID: 33 Comm: ksoftirqd/3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1515 Code: 89 ee e8 78 61 3c f6 40 84 ed 75 21 e8 8e 66 3c f6 44 89 fe bf 07 00 00 00 e8 c1 61 3c f6 41 83 ff 07 74 09 e8 76 66 3c f6 90 <0f> 0b 90 e8 6d 66 3c f6 48 89 df e8 e5 ad ff ff 31 ff 89 c5 89 c6 RSP: 0018:ffffc900006cf338 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888031acd100 RCX: ffffffff8b7f2abf RDX: ffff88801e6ea440 RSI: ffffffff8b7f2aca RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007 R10: 0000000000000004 R11: 0000000000002c10 R12: ffff88802ba69900 R13: 1ffff920000d9e67 R14: ffff888046f81800 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff8880d69bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560fc0ca1670 CR3: 0000000032c3a000 CR4: 0000000000352ef0 Call Trace: <TASK> tcp_data_queue+0x13b0/0x4f90 net/ipv4/tcp_input.c:5197 tcp_rcv_state_process+0xfdf/0x4ec0 net/ipv4/tcp_input.c:6922 tcp_v6_do_rcv+0x492/0x1740 net/ipv6/tcp_ipv6.c:1672 tcp_v6_rcv+0x2976/0x41e0 net/ipv6/tcp_ipv6.c:1918 ip6_protocol_deliver_rcu+0x188/0x1520 net/ipv6/ip6_input.c:438 ip6_input_finish+0x1e4/0x4b0 net/ipv6/ip6_input.c:489 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip6_input+0x105/0x2f0 net/ipv6/ip6_input.c:500 dst_input include/net/dst.h:471 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ipv6_rcv+0x264/0x650 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5979 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092 process_backlog+0x442/0x15e0 net/core/dev.c:6444 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7494 napi_poll net/core/dev.c:7557 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7684 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 run_ksoftirqd kernel/softirq.c:968 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960 smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> The TCP subflow can process the simult-connect syn-ack packet after transitioning to TCP_FIN1 state, bypassing the MPTCP fallback check, as the sk_state_change() callback is not invoked for * -> FIN_WAIT1 transitions. That will move the msk socket to an inconsistent status and the next incoming data will hit the reported splat. Close the race moving the simult-fallback check at the earliest possible stage - that is at syn-ack generation time. About the fixes tags: [2] was supposed to also fix this issue introduced by [3]. [1] is required as a dependence: it was not explicitly marked as a fix, but it is one and it has already been backported before [3]. In other words, this commit should be backported up to [3], including [2] and [1] if that's not already there. Fixes: 23e89e8ee7be ("tcp: Don't drop SYN+ACK for simultaneous connect().") [1] Fixes: 4fd19a307016 ("mptcp: fix inconsistent state on fastopen race") [2] Fixes: 1e777f39b4d7 ("mptcp: add MSG_FASTOPEN sendmsg flag support") [3] Cc: stable@vger.kernel.org Reported-by: syzbot+0ff6b771b4f7a5bce83b@syzkaller.appspotmail.com Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/586 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20251212-net-mptcp-subflow_data_ready-warn-v1-1-d1f9fd1c36c8@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-22net/handshake: Fix null-ptr-deref in handshake_complete()Wang Liang
A null pointer dereference in handshake_complete() was observed [1]. When handshake_req_next() return NULL in handshake_nl_accept_doit(), function handshake_complete() will be called unexpectedly which triggers this crash. Fix it by goto out_status when req is NULL. [1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI RIP: 0010:handshake_complete+0x36/0x2b0 net/handshake/request.c:288 Call Trace: <TASK> handshake_nl_accept_doit+0x32d/0x7e0 net/handshake/netlink.c:129 genl_family_rcv_msg_doit+0x204/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg+0x436/0x670 net/netlink/genetlink.c:1195 genl_rcv_msg+0xcc/0x170 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x14c/0x430 net/netlink/af_netlink.c:2550 genl_rcv+0x2d/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x878/0xb20 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x897/0xd70 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa39/0xbf0 net/socket.c:2592 ___sys_sendmsg+0x121/0x1c0 net/socket.c:2646 __sys_sendmsg+0x155/0x200 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x5f/0x350 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> Fixes: fe67b063f687 ("net/handshake: convert handshake_nl_accept_doit() to FD_PREPARE()") Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/kernel-tls-handshake/aScekpuOYHRM9uOd@morisot.1015granger.net/T/#m7cfa5c11efc626d77622b2981591197a2acdd65e Signed-off-by: Wang Liang <wangliang74@huawei.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20251212012723.4111831-1-wangliang74@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-22ip6_gre: make ip6gre_header() robustEric Dumazet
Over the years, syzbot found many ways to crash the kernel in ip6gre_header() [1]. This involves team or bonding drivers ability to dynamically change their dev->needed_headroom and/or dev->hard_header_len In this particular crash mld_newpack() allocated an skb with a too small reserve/headroom, and by the time mld_sendpack() was called, syzbot managed to attach an ip6gre device. [1] skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8 tail:0x70 end:0x6c0 dev:team0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:213 ! <TASK> skb_under_panic net/core/skbuff.c:223 [inline] skb_push+0xc3/0xe0 net/core/skbuff.c:2641 ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371 dev_hard_header include/linux/netdevice.h:3436 [inline] neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618 neigh_output include/net/neighbour.h:556 [inline] ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318 mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855 mld_send_cr net/ipv6/mcast.c:2154 [inline] mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693 Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Reported-by: syzbot+43a2ebcf2a64b1102d64@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/693b002c.a70a0220.33cd7b.0033.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251211173550.2032674-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-22net: openvswitch: Avoid needlessly taking the RTNL on vport destroyToke Høiland-Jørgensen
The openvswitch teardown code will immediately call ovs_netdev_detach_dev() in response to a NETDEV_UNREGISTER notification. It will then start the dp_notify_work workqueue, which will later end up calling the vport destroy() callback. This callback takes the RTNL to do another ovs_netdev_detach_port(), which in this case is unnecessary. This causes extra pressure on the RTNL, in some cases leading to "unregister_netdevice: waiting for XX to become free" warnings on teardown. We can straight-forwardly avoid the extra RTNL lock acquisition by checking the device flags before taking the lock, and skip the locking altogether if the IFF_OVS_DATAPATH flag has already been unset. Fixes: b07c26511e94 ("openvswitch: fix vport-netdev unregister") Tested-by: Adrian Moreno <amorenoz@redhat.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Eelco Chaudron <echaudro@redhat.com> Acked-by: Aaron Conole <aconole@redhat.com> Link: https://patch.msgid.link/20251211115006.228876-1-toke@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-19Bluetooth: MGMT: report BIS capability flags in supported settingsPauli Virtanen
MGMT_SETTING_ISO_BROADCASTER and MGMT_SETTING_ISO_RECEIVER flags are missing from supported_settings although they are in current_settings. Report them also in supported_settings to be consistent. Fixes: ae7533613133 ("Bluetooth: Check for ISO support in controller") Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-12-19Merge tag 'net-6.19-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from netfilter and CAN. Current release - regressions: - netfilter: nf_conncount: fix leaked ct in error paths - sched: act_mirred: fix loop detection - sctp: fix potential deadlock in sctp_clone_sock() - can: fix build dependency - eth: mlx5e: do not update BQL of old txqs during channel reconfiguration Previous releases - regressions: - sched: ets: always remove class from active list before deleting it - inet: frags: flush pending skbs in fqdir_pre_exit() - netfilter: nf_nat: remove bogus direction check - mptcp: - schedule rtx timer only after pushing data - avoid deadlock on fallback while reinjecting - can: gs_usb: fix error handling - eth: - mlx5e: - avoid unregistering PSP twice - fix double unregister of HCA_PORTS component - bnxt_en: fix XDP_TX path - mlxsw: fix use-after-free when updating multicast route stats Previous releases - always broken: - ethtool: avoid overflowing userspace buffer on stats query - openvswitch: fix middle attribute validation in push_nsh() action - eth: - mlx5: fw_tracer, validate format string parameters - mlxsw: spectrum_router: fix neighbour use-after-free - ipvlan: ignore PACKET_LOOPBACK in handle_mode_l2() Misc: - Jozsef Kadlecsik retires from maintaining netfilter - tools: ynl: fix build on systems with old kernel headers" * tag 'net-6.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits) net: hns3: add VLAN id validation before using net: hns3: using the num_tqps to check whether tqp_index is out of range when vf get ring info from mbx net: hns3: using the num_tqps in the vf driver to apply for resources net: enetc: do not transmit redirected XDP frames when the link is down selftests/tc-testing: Test case exercising potential mirred redirect deadlock net/sched: act_mirred: fix loop detection sctp: Clear inet_opt in sctp_v6_copy_ip_options(). sctp: Fetch inet6_sk() after setting ->pinet6 in sctp_clone_sock(). net/handshake: duplicate handshake cancellations leak socket net/mlx5e: Don't include PSP in the hard MTU calculations net/mlx5e: Do not update BQL of old txqs during channel reconfiguration net/mlx5e: Trigger neighbor resolution for unresolved destinations net/mlx5e: Use ip6_dst_lookup instead of ipv6_dst_lookup_flow for MAC init net/mlx5: Serialize firmware reset with devlink net/mlx5: fw_tracer, Handle escaped percent properly net/mlx5: fw_tracer, Validate format string parameters net/mlx5: Drain firmware reset in shutdown callback net/mlx5: fw reset, clear reset requested on drain_fw_reset net: dsa: mxl-gsw1xx: manually clear RANEG bit net: dsa: mxl-gsw1xx: fix .shutdown driver operation ...
2025-12-18Merge tag 'linux-can-fixes-for-6.19-20251218' of ↵Paolo Abeni
git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can Marc Kleine-Budde says: ==================== pull-request: can 2025-12-18 this is a pull request of 3 patches for net/main. Tetsuo Handa contributes 2 patches to fix race windows in the j1939 protocol to properly handle disappearing network devices. The last patch is by me, it fixes a build dependency with the CAN drivers, that got introduced while fixing a dependency between the CAN protocol and CAN device code. linux-can-fixes-for-6.19-20251218 * tag 'linux-can-fixes-for-6.19-20251218' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can: can: fix build dependency can: j1939: make j1939_sk_bind() fail if device is no longer registered can: j1939: make j1939_session_activate() fail if device is no longer registered ==================== Link: https://patch.msgid.link/20251218123132.664533-1-mkl@pengutronix.de Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-18net/sched: act_mirred: fix loop detectionJamal Hadi Salim
Fix a loop scenario of ethx:egress->ethx:egress Example setup to reproduce: tc qdisc add dev ethx root handle 1: drr tc filter add dev ethx parent 1: protocol ip prio 1 matchall \ action mirred egress redirect dev ethx Now ping out of ethx and you get a deadlock: [ 116.892898][ T307] ============================================ [ 116.893182][ T307] WARNING: possible recursive locking detected [ 116.893418][ T307] 6.18.0-rc6-01205-ge05021a829b8-dirty #204 Not tainted [ 116.893682][ T307] -------------------------------------------- [ 116.893926][ T307] ping/307 is trying to acquire lock: [ 116.894133][ T307] ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50 [ 116.894517][ T307] [ 116.894517][ T307] but task is already holding lock: [ 116.894836][ T307] ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50 [ 116.895252][ T307] [ 116.895252][ T307] other info that might help us debug this: [ 116.895608][ T307] Possible unsafe locking scenario: [ 116.895608][ T307] [ 116.895901][ T307] CPU0 [ 116.896057][ T307] ---- [ 116.896200][ T307] lock(&sch->root_lock_key); [ 116.896392][ T307] lock(&sch->root_lock_key); [ 116.896605][ T307] [ 116.896605][ T307] *** DEADLOCK *** [ 116.896605][ T307] [ 116.896864][ T307] May be due to missing lock nesting notation [ 116.896864][ T307] [ 116.897123][ T307] 6 locks held by ping/307: [ 116.897302][ T307] #0: ffff88800b4b0250 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0xb20/0x2cf0 [ 116.897808][ T307] #1: ffffffff88c839c0 (rcu_read_lock){....}-{1:3}, at: ip_output+0xa9/0x600 [ 116.898138][ T307] #2: ffffffff88c839c0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x2c6/0x1ee0 [ 116.898459][ T307] #3: ffffffff88c83960 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x200/0x3b50 [ 116.898782][ T307] #4: ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50 [ 116.899132][ T307] #5: ffffffff88c83960 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x200/0x3b50 [ 116.899442][ T307] [ 116.899442][ T307] stack backtrace: [ 116.899667][ T307] CPU: 2 UID: 0 PID: 307 Comm: ping Not tainted 6.18.0-rc6-01205-ge05021a829b8-dirty #204 PREEMPT(voluntary) [ 116.899672][ T307] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 116.899675][ T307] Call Trace: [ 116.899678][ T307] <TASK> [ 116.899680][ T307] dump_stack_lvl+0x6f/0xb0 [ 116.899688][ T307] print_deadlock_bug.cold+0xc0/0xdc [ 116.899695][ T307] __lock_acquire+0x11f7/0x1be0 [ 116.899704][ T307] lock_acquire+0x162/0x300 [ 116.899707][ T307] ? __dev_queue_xmit+0x2210/0x3b50 [ 116.899713][ T307] ? srso_alias_return_thunk+0x5/0xfbef5 [ 116.899717][ T307] ? stack_trace_save+0x93/0xd0 [ 116.899723][ T307] _raw_spin_lock+0x30/0x40 [ 116.899728][ T307] ? __dev_queue_xmit+0x2210/0x3b50 [ 116.899731][ T307] __dev_queue_xmit+0x2210/0x3b50 Fixes: 178ca30889a1 ("Revert "net/sched: Fix mirred deadlock on device recursion"") Tested-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/20251210162255.1057663-1-jhs@mojatatu.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-18sctp: Clear inet_opt in sctp_v6_copy_ip_options().Kuniyuki Iwashima
syzbot reported the splat below. [0] Since the cited commit, the child socket inherits all fields of its parent socket unless explicitly cleared. syzbot set IP_OPTIONS to AF_INET6 socket and created a child socket inheriting inet_sk(sk)->inet_opt. sctp_v6_copy_ip_options() only clones np->opt, and leaving inet_opt results in double-free. Let's clear inet_opt in sctp_v6_copy_ip_options(). [0]: BUG: KASAN: double-free in inet_sock_destruct+0x538/0x740 net/ipv4/af_inet.c:159 Free of addr ffff8880304b6d40 by task ksoftirqd/0/15 CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report_invalid_free+0xea/0x110 mm/kasan/report.c:557 check_slab_allocation+0xe1/0x130 include/linux/page-flags.h:-1 kasan_slab_pre_free include/linux/kasan.h:198 [inline] slab_free_hook mm/slub.c:2484 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x148/0x6d0 mm/slub.c:6837 inet_sock_destruct+0x538/0x740 net/ipv4/af_inet.c:159 __sk_destruct+0x89/0x660 net/core/sock.c:2350 sock_put include/net/sock.h:1991 [inline] sctp_endpoint_destroy_rcu+0xa1/0xf0 net/sctp/endpointola.c:197 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x286/0x870 kernel/softirq.c:622 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 6003: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5642 [inline] __kmalloc_noprof+0x411/0x7f0 mm/slub.c:5654 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ip_options_get+0x51/0x4c0 net/ipv4/ip_options.c:517 do_ip_setsockopt+0x1d9b/0x2d00 net/ipv4/ip_sockglue.c:1087 ip_setsockopt+0x66/0x110 net/ipv4/ip_sockglue.c:1417 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2360 __sys_setsockopt net/socket.c:2385 [inline] __do_sys_setsockopt net/socket.c:2391 [inline] __se_sys_setsockopt net/socket.c:2388 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2388 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x19a/0x6d0 mm/slub.c:6837 inet_sock_destruct+0x538/0x740 net/ipv4/af_inet.c:159 __sk_destruct+0x89/0x660 net/core/sock.c:2350 sock_put include/net/sock.h:1991 [inline] sctp_endpoint_destroy_rcu+0xa1/0xf0 net/sctp/endpointola.c:197 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x286/0x870 kernel/softirq.c:622 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Fixes: 16942cf4d3e31 ("sctp: Use sk_clone() in sctp_accept().") Reported-by: syzbot+ec33a1a006ed5abe7309@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6936d112.a70a0220.38f243.00a8.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251210081206.1141086-3-kuniyu@google.com Acked-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-18sctp: Fetch inet6_sk() after setting ->pinet6 in sctp_clone_sock().Kuniyuki Iwashima
syzbot reported the lockdep splat below. [0] sctp_clone_sock() sets the child socket's ipv6_mc_list to NULL, but somehow sock_release() in an error path finally acquires lock_sock() in ipv6_sock_mc_close(). The root cause is that sctp_clone_sock() fetches inet6_sk(newsk) before setting newinet->pinet6, meaning that the parent's ipv6_mc_list was actually cleared. Also, sctp_v6_copy_ip_options() uses inet6_sk() but is called before newinet->pinet6 is set. Let's use inet6_sk() only after setting newinet->pinet6. [0]: WARNING: possible recursive locking detected syzkaller #0 Not tainted syz.0.17/5996 is trying to acquire lock: ffff888031af4c60 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] ffff888031af4c60 (sk_lock-AF_INET6){+.+.}-{0:0}, at: ipv6_sock_mc_close+0xd3/0x140 net/ipv6/mcast.c:348 but task is already holding lock: ffff888031af4320 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] ffff888031af4320 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_getsockopt+0x135/0xb60 net/sctp/socket.c:8131 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sk_lock-AF_INET6); lock(sk_lock-AF_INET6); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by syz.0.17/5996: #0: ffff888031af4320 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline] #0: ffff888031af4320 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_getsockopt+0x135/0xb60 net/sctp/socket.c:8131 stack backtrace: CPU: 0 UID: 0 PID: 5996 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x2540/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 lock_sock_nested+0x48/0x100 net/core/sock.c:3780 lock_sock include/net/sock.h:1700 [inline] ipv6_sock_mc_close+0xd3/0x140 net/ipv6/mcast.c:348 inet6_release+0x47/0x70 net/ipv6/af_inet6.c:482 __sock_release net/socket.c:653 [inline] sock_release+0x85/0x150 net/socket.c:681 sctp_getsockopt_peeloff_common+0x56b/0x770 net/sctp/socket.c:5732 sctp_getsockopt_peeloff_flags+0x13b/0x230 net/sctp/socket.c:5801 sctp_getsockopt+0x3ab/0xb60 net/sctp/socket.c:8151 do_sock_getsockopt+0x2b4/0x3d0 net/socket.c:2399 __sys_getsockopt net/socket.c:2428 [inline] __do_sys_getsockopt net/socket.c:2435 [inline] __se_sys_getsockopt net/socket.c:2432 [inline] __x64_sys_getsockopt+0x1a5/0x250 net/socket.c:2432 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f8c38f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcfdade018 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007f8f8c5e5fa0 RCX: 00007f8f8c38f749 RDX: 000000000000007a RSI: 0000000000000084 RDI: 0000000000000003 RBP: 00007f8f8c413f91 R08: 0000200000000040 R09: 0000000000000000 R10: 0000200000000340 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8f8c5e5fa0 R14: 00007f8f8c5e5fa0 R15: 0000000000000005 </TASK> Fixes: 16942cf4d3e31 ("sctp: Use sk_clone() in sctp_accept().") Reported-by: syzbot+c59e6bb54e7620495725@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6936d112.a70a0220.38f243.00a7.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251210081206.1141086-2-kuniyu@google.com Acked-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>