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2025-05-13net: devmem: Implement TX pathMina Almasry
Augment dmabuf binding to be able to handle TX. Additional to all the RX binding, we also create tx_vec needed for the TX path. Provide API for sendmsg to be able to send dmabufs bound to this device: - Provide a new dmabuf_tx_cmsg which includes the dmabuf to send from. - MSG_ZEROCOPY with SCM_DEVMEM_DMABUF cmsg indicates send from dma-buf. Devmem is uncopyable, so piggyback off the existing MSG_ZEROCOPY implementation, while disabling instances where MSG_ZEROCOPY falls back to copying. We additionally pipe the binding down to the new zerocopy_fill_skb_from_devmem which fills a TX skb with net_iov netmems instead of the traditional page netmems. We also special case skb_frag_dma_map to return the dma-address of these dmabuf net_iovs instead of attempting to map pages. The TX path may release the dmabuf in a context where we cannot wait. This happens when the user unbinds a TX dmabuf while there are still references to its netmems in the TX path. In that case, the netmems will be put_netmem'd from a context where we can't unmap the dmabuf, Resolve this by making __net_devmem_dmabuf_binding_free schedule_work'd. Based on work by Stanislav Fomichev <sdf@fomichev.me>. A lot of the meat of the implementation came from devmem TCP RFC v1[1], which included the TX path, but Stan did all the rebasing on top of netmem/net_iov. Cc: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250508004830.4100853-5-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-05ipv4: ip_tunnel: Replace strcpy use with strscpyRuben Wauters
Use of strcpy is decpreated, replaces the use of strcpy with strscpy as recommended. strscpy was chosen as it requires a NUL terminated non-padded string, which is the case here. I am aware there is an explicit bounds check above the second instance, however using strscpy protects against buffer overflows in any future code, and there is no good reason I can see to not use it. I have also replaced the scrscpy above that had 3 params with the version using 2 params. These are functionally equivalent, but it is cleaner to have both using 2 params. Signed-off-by: Ruben Wauters <rubenru09@aol.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250501202935.46318-1-rubenru09@aol.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-05Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Martin KaFai Lau says: ==================== pull-request: bpf-next 2025-05-02 We've added 14 non-merge commits during the last 10 day(s) which contain a total of 13 files changed, 740 insertions(+), 121 deletions(-). The main changes are: 1) Avoid skipping or repeating a sk when using a UDP bpf_iter, from Jordan Rife. 2) Fixed a crash when a bpf qdisc is set in the net.core.default_qdisc, from Amery Hung. 3) A few other fixes in the bpf qdisc, from Amery Hung. - Always call qdisc_watchdog_init() in the .init prologue such that the .reset/.destroy epilogue can always call qdisc_watchdog_cancel() without issue. - bpf_qdisc_init_prologue() was incorrectly returning an error when the bpf qdisc is set as the default_qdisc and the mq is creating the default_qdisc. It is now fixed. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: selftests/bpf: Cleanup bpf qdisc selftests selftests/bpf: Test attaching a bpf qdisc with incomplete operators bpf: net_sched: Make some Qdisc_ops ops mandatory selftests/bpf: Test setting and creating bpf qdisc as default qdisc bpf: net_sched: Fix bpf qdisc init prologue when set as default qdisc selftests/bpf: Add tests for bucket resume logic in UDP socket iterators selftests/bpf: Return socket cookies from sock_iter_batch progs bpf: udp: Avoid socket skips and repeats during iteration bpf: udp: Use bpf_udp_iter_batch_item for bpf_udp_iter_state batch items bpf: udp: Get rid of st_bucket_done bpf: udp: Make sure iter->batch always contains a full bucket snapshot bpf: udp: Make mem flags configurable through bpf_iter_udp_realloc_batch bpf: net_sched: Fix using bpf qdisc as default qdisc selftests/bpf: Fix compilation errors ==================== Link: https://patch.msgid.link/20250503010755.4030524-1-martin.lau@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-03ipv4: Honor "ignore_routes_with_linkdown" sysctl in nexthop selectionIdo Schimmel
Commit 32607a332cfe ("ipv4: prefer multipath nexthop that matches source address") changed IPv4 nexthop selection to prefer a nexthop whose nexthop device is assigned the specified source address for locally generated traffic. While the selection honors the "fib_multipath_use_neigh" sysctl and will not choose a nexthop with an invalid neighbour, it does not honor the "ignore_routes_with_linkdown" sysctl and can choose a nexthop without a carrier: $ sysctl net.ipv4.conf.all.ignore_routes_with_linkdown net.ipv4.conf.all.ignore_routes_with_linkdown = 1 $ ip route show 198.51.100.0/24 198.51.100.0/24 nexthop via 192.0.2.2 dev dummy1 weight 1 nexthop via 192.0.2.18 dev dummy2 weight 1 dead linkdown $ ip route get 198.51.100.1 from 192.0.2.17 198.51.100.1 from 192.0.2.17 via 192.0.2.18 dev dummy2 uid 0 Solve this by skipping over nexthops whose assigned hash upper bound is minus one, which is the value assigned to nexthops that do not have a carrier when the "ignore_routes_with_linkdown" sysctl is set. In practice, this probably does not matter a lot as the initial route lookup for the source address would not choose a nexthop that does not have a carrier in the first place, but the change does make the code clearer. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-05-02bpf: udp: Avoid socket skips and repeats during iterationJordan Rife
Replace the offset-based approach for tracking progress through a bucket in the UDP table with one based on socket cookies. Remember the cookies of unprocessed sockets from the last batch and use this list to pick up where we left off or, in the case that the next socket disappears between reads, find the first socket after that point that still exists in the bucket and resume from there. This approach guarantees that all sockets that existed when iteration began and continue to exist throughout will be visited exactly once. Sockets that are added to the table during iteration may or may not be seen, but if they are they will be seen exactly once. Signed-off-by: Jordan Rife <jordan@jrife.io> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2025-05-02bpf: udp: Use bpf_udp_iter_batch_item for bpf_udp_iter_state batch itemsJordan Rife
Prepare for the next patch that tracks cookies between iterations by converting struct sock **batch to union bpf_udp_iter_batch_item *batch inside struct bpf_udp_iter_state. Signed-off-by: Jordan Rife <jordan@jrife.io> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
2025-05-02bpf: udp: Get rid of st_bucket_doneJordan Rife
Get rid of the st_bucket_done field to simplify UDP iterator state and logic. Before, st_bucket_done could be false if bpf_iter_udp_batch returned a partial batch; however, with the last patch ("bpf: udp: Make sure iter->batch always contains a full bucket snapshot"), st_bucket_done == true is equivalent to iter->cur_sk == iter->end_sk. Signed-off-by: Jordan Rife <jordan@jrife.io> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2025-05-02bpf: udp: Make sure iter->batch always contains a full bucket snapshotJordan Rife
Require that iter->batch always contains a full bucket snapshot. This invariant is important to avoid skipping or repeating sockets during iteration when combined with the next few patches. Before, there were two cases where a call to bpf_iter_udp_batch may only capture part of a bucket: 1. When bpf_iter_udp_realloc_batch() returns -ENOMEM [1]. 2. When more sockets are added to the bucket while calling bpf_iter_udp_realloc_batch(), making the updated batch size insufficient [2]. In cases where the batch size only covers part of a bucket, it is possible to forget which sockets were already visited, especially if we have to process a bucket in more than two batches. This forces us to choose between repeating or skipping sockets, so don't allow this: 1. Stop iteration and propagate -ENOMEM up to userspace if reallocation fails instead of continuing with a partial batch. 2. Try bpf_iter_udp_realloc_batch() with GFP_USER just as before, but if we still aren't able to capture the full bucket, call bpf_iter_udp_realloc_batch() again while holding the bucket lock to guarantee the bucket does not change. On the second attempt use GFP_NOWAIT since we hold onto the spin lock. Introduce the udp_portaddr_for_each_entry_from macro and use it instead of udp_portaddr_for_each_entry to make it possible to continue iteration from an arbitrary socket. This is required for this patch in the GFP_NOWAIT case to allow us to fill the rest of a batch starting from the middle of a bucket and the later patch which skips sockets that were already seen. Testing all scenarios directly is a bit difficult, but I did some manual testing to exercise the code paths where GFP_NOWAIT is used and where ERR_PTR(err) is returned. I used the realloc test case included later in this series to trigger a scenario where a realloc happens inside bpf_iter_udp_batch and made a small code tweak to force the first realloc attempt to allocate a too-small batch, thus requiring another attempt with GFP_NOWAIT. Some printks showed both reallocs with the tests passing: Apr 25 23:16:24 crow kernel: go again GFP_USER Apr 25 23:16:24 crow kernel: go again GFP_NOWAIT With this setup, I also forced each of the bpf_iter_udp_realloc_batch calls to return -ENOMEM to ensure that iteration ends and that the read() in userspace fails. [1]: https://lore.kernel.org/bpf/CABi4-ogUtMrH8-NVB6W8Xg_F_KDLq=yy-yu-tKr2udXE2Mu1Lg@mail.gmail.com/ [2]: https://lore.kernel.org/bpf/7ed28273-a716-4638-912d-f86f965e54bb@linux.dev/ Signed-off-by: Jordan Rife <jordan@jrife.io> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2025-05-02bpf: udp: Make mem flags configurable through bpf_iter_udp_realloc_batchJordan Rife
Prepare for the next patch which needs to be able to choose either GFP_USER or GFP_NOWAIT for calls to bpf_iter_udp_realloc_batch. Signed-off-by: Jordan Rife <jordan@jrife.io> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
2025-05-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.15-rc5). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-01net: use sock_gen_put() when sk_state is TCP_TIME_WAITJibin Zhang
It is possible for a pointer of type struct inet_timewait_sock to be returned from the functions __inet_lookup_established() and __inet6_lookup_established(). This can cause a crash when the returned pointer is of type struct inet_timewait_sock and sock_put() is called on it. The following is a crash call stack that shows sk->sk_wmem_alloc being accessed in sk_free() during the call to sock_put() on a struct inet_timewait_sock pointer. To avoid this issue, use sock_gen_put() instead of sock_put() when sk->sk_state is TCP_TIME_WAIT. mrdump.ko ipanic() + 120 vmlinux notifier_call_chain(nr_to_call=-1, nr_calls=0) + 132 vmlinux atomic_notifier_call_chain(val=0) + 56 vmlinux panic() + 344 vmlinux add_taint() + 164 vmlinux end_report() + 136 vmlinux kasan_report(size=0) + 236 vmlinux report_tag_fault() + 16 vmlinux do_tag_recovery() + 16 vmlinux __do_kernel_fault() + 88 vmlinux do_bad_area() + 28 vmlinux do_tag_check_fault() + 60 vmlinux do_mem_abort() + 80 vmlinux el1_abort() + 56 vmlinux el1h_64_sync_handler() + 124 vmlinux > 0xFFFFFFC080011294() vmlinux __lse_atomic_fetch_add_release(v=0xF2FFFF82A896087C) vmlinux __lse_atomic_fetch_sub_release(v=0xF2FFFF82A896087C) vmlinux arch_atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C) + 8 vmlinux raw_atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C) + 8 vmlinux atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C) + 8 vmlinux __refcount_sub_and_test(i=1, r=0xF2FFFF82A896087C, oldp=0) + 8 vmlinux __refcount_dec_and_test(r=0xF2FFFF82A896087C, oldp=0) + 8 vmlinux refcount_dec_and_test(r=0xF2FFFF82A896087C) + 8 vmlinux sk_free(sk=0xF2FFFF82A8960700) + 28 vmlinux sock_put() + 48 vmlinux tcp6_check_fraglist_gro() + 236 vmlinux tcp6_gro_receive() + 624 vmlinux ipv6_gro_receive() + 912 vmlinux dev_gro_receive() + 1116 vmlinux napi_gro_receive() + 196 ccmni.ko ccmni_rx_callback() + 208 ccmni.ko ccmni_queue_recv_skb() + 388 ccci_dpmaif.ko dpmaif_rxq_push_thread() + 1088 vmlinux kthread() + 268 vmlinux 0xFFFFFFC08001F30C() Fixes: c9d1d23e5239 ("net: add heuristic for enabling TCP fraglist GRO") Signed-off-by: Jibin Zhang <jibin.zhang@mediatek.com> Signed-off-by: Shiming Cheng <shiming.cheng@mediatek.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://patch.msgid.link/20250429020412.14163-1-shiming.cheng@mediatek.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-29Merge tag 'nf-next-25-04-29' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following batch contains Netfilter updates for net-next: 1) Replace msecs_to_jiffies() by secs_to_jiffies(), from Easwar Hariharan. 2) Allow to compile xt_cgroup with cgroupsv2 support only, from Michal Koutny. 3) Prepare for sock_cgroup_classid() removal by wrapping it around ifdef, also from Michal Koutny. 4) Remove redundant pointer fetch on conntrack template, from Xuanqiang Luo. 5) Re-format one block in the tproxy documentation for consistency, from Chen Linxuan. 6) Expose set element count and type via netlink attributes, from Florian Westphal. * tag 'nf-next-25-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nf_tables: export set count and backend name to userspace docs: tproxy: fix formatting for nft code block netfilter: conntrack: Remove redundant NFCT_ALIGN call net: cgroup: Guard users of sock_cgroup_classid() netfilter: xt_cgroup: Make it independent from net_cls netfilter: xt_IDLETIMER: convert timeouts to secs_to_jiffies() ==================== Link: https://patch.msgid.link/20250428221254.3853-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-29net: ipv6: fix UDPv6 GSO segmentation with NATFelix Fietkau
If any address or port is changed, update it in all packets and recalculate checksum. Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Signed-off-by: Felix Fietkau <nbd@nbd.name> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250426153210.14044-1-nbd@nbd.name Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-29ipv4: fib: Fix fib_info_hash_alloc() allocation typeKees Cook
In preparation for making the kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.) This was allocating many sizeof(struct hlist_head *) when it actually wanted sizeof(struct hlist_head). Luckily these are the same size. Adjust the allocation type to match the assignment. Signed-off-by: Kees Cook <kees@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250426060529.work.873-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-29ip: load balance tcp connections to single dst addr and portWillem de Bruijn
Load balance new TCP connections across nexthops also when they connect to the same service at a single remote address and port. This affects only port-based multipath hashing: fib_multipath_hash_policy 1 or 3. Local connections must choose both a source address and port when connecting to a remote service, in ip_route_connect. This "chicken-and-egg problem" (commit 2d7192d6cbab ("ipv4: Sanitize and simplify ip_route_{connect,newports}()")) is resolved by first selecting a source address, by looking up a route using the zero wildcard source port and address. As a result multiple connections to the same destination address and port have no entropy in fib_multipath_hash. This is not a problem when forwarding, as skb-based hashing has a 4-tuple. Nor when establishing UDP connections, as autobind there selects a port before reaching ip_route_connect. Load balance also TCP, by using a random port in fib_multipath_hash. Port assignment in inet_hash_connect is not atomic with ip_route_connect. Thus ports are unpredictable, effectively random. Implementation details: Do not actually pass a random fl4_sport, as that affects not only hashing, but routing more broadly, and can match a source port based policy route, which existing wildcard port 0 will not. Instead, define a new wildcard flowi flag that is used only for hashing. Selecting a random source is equivalent to just selecting a random hash entirely. But for code clarity, follow the normal 4-tuple hash process and only update this field. fib_multipath_hash can be reached with zero sport from other code paths, so explicitly pass this flowi flag, rather than trying to infer this case in the function itself. Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250424143549.669426-3-willemdebruijn.kernel@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-29ipv4: prefer multipath nexthop that matches source addressWillem de Bruijn
With multipath routes, try to ensure that packets leave on the device that is associated with the source address. Avoid the following tcpdump example: veth0 Out IP 10.1.0.2.38640 > 10.2.0.3.8000: Flags [S] veth1 Out IP 10.1.0.2.38648 > 10.2.0.3.8000: Flags [S] Which can happen easily with the most straightforward setup: ip addr add 10.0.0.1/24 dev veth0 ip addr add 10.1.0.1/24 dev veth1 ip route add 10.2.0.3 nexthop via 10.0.0.2 dev veth0 \ nexthop via 10.1.0.2 dev veth1 This is apparently considered WAI, based on the comment in ip_route_output_key_hash_rcu: * 2. Moreover, we are allowed to send packets with saddr * of another iface. --ANK It may be ok for some uses of multipath, but not all. For instance, when using two ISPs, a router may drop packets with unknown source. The behavior occurs because tcp_v4_connect makes three route lookups when establishing a connection: 1. ip_route_connect calls to select a source address, with saddr zero. 2. ip_route_connect calls again now that saddr and daddr are known. 3. ip_route_newports calls again after a source port is also chosen. With a route with multiple nexthops, each lookup may make a different choice depending on available entropy to fib_select_multipath. So it is possible for 1 to select the saddr from the first entry, but 3 to select the second entry. Leading to the above situation. Address this by preferring a match that matches the flowi4 saddr. This will make 2 and 3 make the same choice as 1. Continue to update the backup choice until a choice that matches saddr is found. Do this in fib_select_multipath itself, rather than passing an fl4_oif constraint, to avoid changing non-multipath route selection. Commit e6b45241c57a ("ipv4: reset flowi parameters on route connect") shows how that may cause regressions. Also read ipv4.sysctl_fib_multipath_use_neigh only once. No need to refresh in the loop. This does not happen in IPv6, which performs only one lookup. Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250424143549.669426-2-willemdebruijn.kernel@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-24tcp: fastopen: pass TFO child indication through getsockoptJeremy Harris
tcp: fastopen: pass TFO child indication through getsockopt Note that this uses up the last bit of a field in struct tcp_info Signed-off-by: Jeremy Harris <jgh@exim.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250423124334.4916-3-jgh@exim.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-24tcp: fastopen: note that a child socket was createdJeremy Harris
tcp: fastopen: note that a child socket was created This uses up the last bit in a field of tcp_sock. Signed-off-by: Jeremy Harris <jgh@exim.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250423124334.4916-2-jgh@exim.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-24net: ip_gre: Fix spelling mistake "demultiplexor" -> "demultiplexer"Colin Ian King
There is a spelling mistake in a pr_info message. Fix it. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Link: https://patch.msgid.link/20250423113719.173539-1-colin.i.king@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-24net: cgroup: Guard users of sock_cgroup_classid()Michal Koutný
Exclude code that relies on sock_cgroup_classid() as preparation of removal of the function. Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-04-24ipv6: Get rid of RTNL for SIOCADDRT and RTM_NEWROUTE.Kuniyuki Iwashima
Now we are ready to remove RTNL from SIOCADDRT and RTM_NEWROUTE. The remaining things to do are 1. pass false to lwtunnel_valid_encap_type_attr() 2. use rcu_dereference_rtnl() in fib6_check_nexthop() 3. place rcu_read_lock() before ip6_route_info_create_nh(). Let's complete the RTNL-free conversion. When each CPU-X adds 100000 routes on table-X in a batch concurrently on c7a.metal-48xl EC2 instance with 192 CPUs, without this series: $ sudo ./route_test.sh ... added 19200000 routes (100000 routes * 192 tables). time elapsed: 191577 milliseconds. with this series: $ sudo ./route_test.sh ... added 19200000 routes (100000 routes * 192 tables). time elapsed: 62854 milliseconds. I changed the number of routes in each table (1000 ~ 100000) and consistently saw it finish 3x faster with this series. Note that now every caller of lwtunnel_valid_encap_type() passes false as the last argument, and this can be removed later. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250418000443.43734-16-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-24ipv6: Protect nh->f6i_list with spinlock and flag.Kuniyuki Iwashima
We will get rid of RTNL from RTM_NEWROUTE and SIOCADDRT. Then, we may be going to add a route tied to a dying nexthop. The nexthop itself is not freed during the RCU grace period, but if we link a route after __remove_nexthop_fib() is called for the nexthop, the route will be leaked. To avoid the race between IPv6 route addition under RCU vs nexthop deletion under RTNL, let's add a dead flag and protect it and nh->f6i_list with a spinlock. __remove_nexthop_fib() acquires the nexthop's spinlock and sets false to nh->dead, then calls ip6_del_rt() for the linked route one by one without the spinlock because fib6_purge_rt() acquires it later. While adding an IPv6 route, fib6_add() acquires the nexthop lock and checks the dead flag just before inserting the route. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250418000443.43734-15-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-24ipv6: Preallocate nhc_pcpu_rth_output in ip6_route_info_create().Kuniyuki Iwashima
ip6_route_info_create_nh() will be called under RCU. It calls fib_nh_common_init() and allocates nhc->nhc_pcpu_rth_output. As with the reason for rt->fib6_nh->rt6i_pcpu, we want to avoid GFP_ATOMIC allocation for nhc->nhc_pcpu_rth_output under RCU. Let's preallocate it in ip6_route_info_create(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250418000443.43734-9-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-04-17xfrm: Fix UDP GRO handling for some corner casesTobias Brunner
This fixes an issue that's caused if there is a mismatch between the data offset in the GRO header and the length fields in the regular sk_buff due to the pskb_pull()/skb_push() calls. That's because the UDP GRO layer stripped off the UDP header via skb_gro_pull() already while the UDP header was explicitly not pulled/pushed in this function. For example, an IKE packet that triggered this had len=data_len=1268 and the data_offset in the GRO header was 28 (IPv4 + UDP). So pskb_pull() was called with an offset of 28-8=20, which reduced len to 1248 and via pskb_may_pull() and __pskb_pull_tail() it also set data_len to 1248. As the ESP offload module was not loaded, the function bailed out and called skb_push(), which restored len to 1268, however, data_len remained at 1248. So while skb_headlen() was 0 before, it was now 20. The latter caused a difference of 8 instead of 28 (or 0 if pskb_pull()/skb_push() was called with the complete GRO data_offset) in gro_try_pull_from_frag0() that triggered a call to gro_pull_from_frag0() that corrupted the packet. This change uses a more GRO-like approach seen in other GRO receivers via skb_gro_header() to just read the actual data we are interested in and does not try to "restore" the UDP header at this point to call the existing function. If the offload module is not loaded, it immediately bails out, otherwise, it only does a quick check to see if the packet is an IKE or keepalive packet instead of calling the existing function. Fixes: 172bf009c18d ("xfrm: Support GRO for IPv4 ESP in UDP encapsulation") Fixes: 221ddb723d90 ("xfrm: Support GRO for IPv6 ESP in UDP encapsulation") Signed-off-by: Tobias Brunner <tobias@strongswan.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2025-04-16ipv4: Use nlmsg_payload in ipmr fileBreno Leitao
Leverage the new nlmsg_payload() helper to avoid checking for message size and then reading the nlmsg data. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250415-nlmsg_v2-v1-7-a1c75d493fd7@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-16ipv4: Use nlmsg_payload in route fileBreno Leitao
Leverage the new nlmsg_payload() helper to avoid checking for message size and then reading the nlmsg data. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250415-nlmsg_v2-v1-6-a1c75d493fd7@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-16ipv4: Use nlmsg_payload in fib_frontend fileBreno Leitao
Leverage the new nlmsg_payload() helper to avoid checking for message size and then reading the nlmsg data. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250415-nlmsg_v2-v1-5-a1c75d493fd7@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-16ipv4: Use nlmsg_payload in devinet fileBreno Leitao
Leverage the new nlmsg_payload() helper to avoid checking for message size and then reading the nlmsg data. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250415-nlmsg_v2-v1-4-a1c75d493fd7@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14ipv4: ip_tunnel: Convert ip_tunnel_delete_nets() callers to ->exit_rtnl().Kuniyuki Iwashima
ip_tunnel_delete_nets() iterates the dying netns list and performs the same operations for each. Let's export ip_tunnel_destroy() as ip_tunnel_delete_net() and call it from ->exit_rtnl(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20250411205258.63164-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14nexthop: Convert nexthop_net_exit_batch_rtnl() to ->exit_rtnl().Kuniyuki Iwashima
nexthop_net_exit_batch_rtnl() iterates the dying netns list and performs the same operation for each. Let's use ->exit_rtnl(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20250411205258.63164-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14udp: properly deal with xfrm encap and ADDRFORMPaolo Abeni
UDP GRO accounting assumes that the GRO receive callback is always set when the UDP tunnel is enabled, but syzkaller proved otherwise, leading tot the following splat: WARNING: CPU: 0 PID: 5837 at net/ipv4/udp_offload.c:123 udp_tunnel_update_gro_rcv+0x28d/0x4c0 net/ipv4/udp_offload.c:123 Modules linked in: CPU: 0 UID: 0 PID: 5837 Comm: syz-executor850 Not tainted 6.14.0-syzkaller-13320-g420aabef3ab5 #0 PREEMPT(full) Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:udp_tunnel_update_gro_rcv+0x28d/0x4c0 net/ipv4/udp_offload.c:123 Code: 00 00 e8 c6 5a 2f f7 48 c1 e5 04 48 8d b5 20 53 c7 9a ba 10 00 00 00 4c 89 ff e8 ce 87 99 f7 e9 ce 00 00 00 e8 a4 5a 2f f7 90 <0f> 0b 90 e9 de fd ff ff bf 01 00 00 00 89 ee e8 cf 5e 2f f7 85 ed RSP: 0018:ffffc90003effa88 EFLAGS: 00010293 RAX: ffffffff8a93fc9c RBX: 0000000000000000 RCX: ffff8880306f9e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff8a93fabe R09: 1ffffffff20bfb2e R10: dffffc0000000000 R11: fffffbfff20bfb2f R12: ffff88814ef21738 R13: dffffc0000000000 R14: ffff88814ef21778 R15: 1ffff11029de42ef FS: 0000000000000000(0000) GS:ffff888124f96000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f04eec760d0 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> udp_tunnel_cleanup_gro include/net/udp_tunnel.h:205 [inline] udpv6_destroy_sock+0x212/0x270 net/ipv6/udp.c:1829 sk_common_release+0x71/0x2e0 net/core/sock.c:3896 inet_release+0x17d/0x200 net/ipv4/af_inet.c:435 __sock_release net/socket.c:647 [inline] sock_close+0xbc/0x240 net/socket.c:1391 __fput+0x3e9/0x9f0 fs/file_table.c:465 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa11/0x27f0 kernel/exit.c:953 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f04eebfac79 Code: Unable to access opcode bytes at 0x7f04eebfac4f. RSP: 002b:00007fffdcaa34a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f04eebfac79 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007f04eec75270 R08: ffffffffffffffb8 R09: 00007fffdcaa36c8 R10: 0000200000000000 R11: 0000000000000246 R12: 00007f04eec75270 R13: 0000000000000000 R14: 00007f04eec75cc0 R15: 00007f04eebcca70 Address the issue moving the accounting hook into setup_udp_tunnel_sock() and set_xfrm_gro_udp_encap_rcv(), where the GRO callback is actually set. set_xfrm_gro_udp_encap_rcv() is prone to races with IPV6_ADDRFORM, run the relevant setsockopt under the socket lock to ensure using consistent values of sk_family and up->encap_type. Refactor the GRO callback selection code, to make it clear that the function pointer is always initialized. Reported-by: syzbot+8c469a2260132cd095c1@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=8c469a2260132cd095c1 Fixes: 172bf009c18d ("xfrm: Support GRO for IPv4 ESP in UDP encapsulation") Fixes: 5d7f5b2f6b935 ("udp_tunnel: use static call for GRO hooks when possible") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/92bcdb6899145a9a387c8fa9e3ca656642a43634.1744228733.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14espintcp: remove encap socket caching to avoid reference leakSabrina Dubroca
The current scheme for caching the encap socket can lead to reference leaks when we try to delete the netns. The reference chain is: xfrm_state -> enacp_sk -> netns Since the encap socket is a userspace socket, it holds a reference on the netns. If we delete the espintcp state (through flush or individual delete) before removing the netns, the reference on the socket is dropped and the netns is correctly deleted. Otherwise, the netns may not be reachable anymore (if all processes within the ns have terminated), so we cannot delete the xfrm state to drop its reference on the socket. This patch results in a small (~2% in my tests) performance regression. A GC-type mechanism could be added for the socket cache, to clear references if the state hasn't been used "recently", but it's a lot more complex than just not caching the socket. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2025-04-14espintcp: fix skb leaksSabrina Dubroca
A few error paths are missing a kfree_skb. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2025-04-11tcp: Rename tcp_or_dccp_get_hashinfo().Kuniyuki Iwashima
DCCP was removed, so tcp_or_dccp_get_hashinfo() should be renamed. Let's rename it to tcp_get_hashinfo(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250410023921.11307-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-11net: Unexport shared functions for DCCP.Kuniyuki Iwashima
DCCP was removed, so many inet functions no longer need to be exported. Let's unexport or use EXPORT_IPV6_MOD() for such functions. sk_free_unlock_clone() is inlined in sk_clone_lock() as it's the only caller. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250410023921.11307-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-11net: Retire DCCP socket.Kuniyuki Iwashima
DCCP was orphaned in 2021 by commit 054c4610bd05 ("MAINTAINERS: dccp: move Gerrit Renker to CREDITS"), which noted that the last maintainer had been inactive for five years. In recent years, it has become a playground for syzbot, and most changes to DCCP have been odd bug fixes triggered by syzbot. Apart from that, the only changes have been driven by treewide or networking API updates or adjustments related to TCP. Thus, in 2023, we announced we would remove DCCP in 2025 via commit b144fcaf46d4 ("dccp: Print deprecation notice."). Since then, only one individual has contacted the netdev mailing list. [0] There is ongoing research for Multipath DCCP. The repository is hosted on GitHub [1], and development is not taking place through the upstream community. While the repository is published under the GPLv2 license, the scheduling part remains proprietary, with a LICENSE file [2] stating: "This is not Open Source software." The researcher mentioned a plan to address the licensing issue, upstream the patches, and step up as a maintainer, but there has been no further communication since then. Maintaining DCCP for a decade without any real users has become a burden. Therefore, it's time to remove it. Removing DCCP will also provide significant benefits to TCP. It allows us to freely reorganize the layout of struct inet_connection_sock, which is currently shared with DCCP, and optimize it to reduce the number of cachelines accessed in the TCP fast path. Note that we keep DCCP netfilter modules as requested. [3] Link: https://lore.kernel.org/netdev/20230710182253.81446-1-kuniyu@amazon.com/T/#u #[0] Link: https://github.com/telekom/mp-dccp #[1] Link: https://github.com/telekom/mp-dccp/blob/mpdccp_v03_k5.10/net/dccp/non_gpl_scheduler/LICENSE #[2] Link: https://lore.kernel.org/netdev/Z_VQ0KlCRkqYWXa-@calendula/ #[3] Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Paul Moore <paul@paul-moore.com> (LSM and SELinux) Acked-by: Casey Schaufler <casey@schaufler-ca.com> Link: https://patch.msgid.link/20250410023921.11307-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-10ipv4: remove unnecessary judgment in ip_route_output_key_hash_rcuZhengchao Shao
In the ip_route_output_key_cash_rcu function, the input fl4 member saddr is first checked to be non-zero before entering multicast, broadcast and arbitrary IP address checks. However, the fact that the IP address is not 0 has already ruled out the possibility of any address, so remove unnecessary judgment. Signed-off-by: Zhengchao Shao <shaozhengchao@163.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250409033321.108244-1-shaozhengchao@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-10trace: tcp: Add tracepoint for tcp_sendmsg_locked()Breno Leitao
Add a tracepoint to monitor TCP send operations, enabling detailed visibility into TCP message transmission. Create a new tracepoint within the tcp_sendmsg_locked function, capturing traditional fields along with size_goal, which indicates the optimal data size for a single TCP segment. Additionally, a reference to the struct sock sk is passed, allowing direct access for BPF programs. The implementation is largely based on David's patch[1] and suggestions. Link: https://lore.kernel.org/all/70168c8f-bf52-4279-b4c4-be64527aa1ac@kernel.org/ [1] Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250408-tcpsendmsg-v3-2-208b87064c28@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-10tcp: add LINUX_MIB_PAWS_TW_REJECTED counterJiayuan Chen
When TCP is in TIME_WAIT state, PAWS verification uses LINUX_PAWSESTABREJECTED, which is ambiguous and cannot be distinguished from other PAWS verification processes. We added a new counter, like the existing PAWS_OLD_ACK one. Also we update the doc with previously missing PAWS_OLD_ACK. usage: ''' nstat -az | grep PAWSTimewait TcpExtPAWSTimewait 1 0.0 ''' Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250409112614.16153-3-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-10tcp: add TCP_RFC7323_TW_PAWS drop reasonJiayuan Chen
Devices in the networking path, such as firewalls, NATs, or routers, which can perform SNAT or DNAT, use addresses from their own limited address pools to masquerade the source address during forwarding, causing PAWS verification to fail more easily. Currently, packet loss statistics for PAWS can only be viewed through MIB, which is a global metric and cannot be precisely obtained through tracing to get the specific 4-tuple of the dropped packet. In the past, we had to use kprobe ret to retrieve relevant skb information from tcp_timewait_state_process(). We add a drop_reason pointer, similar to what previous commit does: commit e34100c2ecbb ("tcp: add a drop_reason pointer to tcp_check_req()") This commit addresses the PAWSESTABREJECTED case and also sets the corresponding drop reason. We use 'pwru' to test. Before this commit: '''' ./pwru 'port 9999' 2025/04/07 13:40:19 Listening for events.. TUPLE FUNC 172.31.75.115:12345->172.31.75.114:9999(tcp) sk_skb_reason_drop(SKB_DROP_REASON_NOT_SPECIFIED) ''' After this commit: ''' ./pwru 'port 9999' 2025/04/07 13:51:34 Listening for events.. TUPLE FUNC 172.31.75.115:12345->172.31.75.114:9999(tcp) sk_skb_reason_drop(SKB_DROP_REASON_TCP_RFC7323_TW_PAWS) ''' Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250409112614.16153-2-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.15-rc2). Conflict: Documentation/networking/netdevices.rst net/core/lock_debug.c 04efcee6ef8d ("net: hold instance lock during NETDEV_CHANGE") 03df156dd3a6 ("xdp: double protect netdev->xdp_flags with netdev->lock") No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-08net: Drop unused @sk of __skb_try_recv_from_queue()Michal Luczaj
__skb_try_recv_from_queue() deals with a queue, @sk is not used since commit e427cad6eee4 ("net: datagram: drop 'destructor' argument from several helpers"). Remove sk from function parameters, adapt callers. No functional change intended. Signed-off-by: Michal Luczaj <mhal@rbox.co> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20250407-cleanup-drop-param-sk-v1-1-cd076979afac@rbox.co Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-08udp_tunnel: use static call for GRO hooks when possiblePaolo Abeni
It's quite common to have a single UDP tunnel type active in the whole system. In such a case we can replace the indirect call for the UDP tunnel GRO callback with a static call. Add the related accounting in the control path and switch to static call when possible. To keep the code simple use a static array for the registered tunnel types, and size such array based on the kernel config. Note that there are valid kernel configurations leading to UDP_MAX_TUNNEL_TYPES == 0 even with IS_ENABLED(CONFIG_NET_UDP_TUNNEL), Explicitly skip the accounting in such a case, to avoid compile warning when accessing "udp_tunnel_gro_types". Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/53d156cdfddcc9678449e873cc83e68fa1582653.1744040675.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-08udp_tunnel: create a fastpath GRO lookup.Paolo Abeni
Most UDP tunnels bind a socket to a local port, with ANY address, no peer and no interface index specified. Additionally it's quite common to have a single tunnel device per namespace. Track in each namespace the UDP tunnel socket respecting the above. When only a single one is present, store a reference in the netns. When such reference is not NULL, UDP tunnel GRO lookup just need to match the incoming packet destination port vs the socket local port. The tunnel socket never sets the reuse[port] flag[s]. When bound to no address and interface, no other socket can exist in the same netns matching the specified local port. Matching packets with non-local destination addresses will be aggregated, and eventually segmented as needed - no behavior changes intended. Restrict the optimization to kernel sockets only: it covers all the relevant use-cases, and user-space owned sockets could be disconnected and rebound after setup_udp_tunnel_sock(), breaking the uniqueness assumption Note that the UDP tunnel socket reference is stored into struct netns_ipv4 for both IPv4 and IPv6 tunnels. That is intentional to keep all the fastpath-related netns fields in the same struct and allow cacheline-based optimization. Currently both the IPv4 and IPv6 socket pointer share the same cacheline as the `udp_table` field. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/41d16bc8d1257d567f9344c445b4ae0b4a91ede4.1744040675.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-05treewide: Switch/rename to timer_delete[_sync]()Thomas Gleixner
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-03net: fix geneve_opt length integer overflowLin Ma
struct geneve_opt uses 5 bit length for each single option, which means every vary size option should be smaller than 128 bytes. However, all current related Netlink policies cannot promise this length condition and the attacker can exploit a exact 128-byte size option to *fake* a zero length option and confuse the parsing logic, further achieve heap out-of-bounds read. One example crash log is like below: [ 3.905425] ================================================================== [ 3.905925] BUG: KASAN: slab-out-of-bounds in nla_put+0xa9/0xe0 [ 3.906255] Read of size 124 at addr ffff888005f291cc by task poc/177 [ 3.906646] [ 3.906775] CPU: 0 PID: 177 Comm: poc-oob-read Not tainted 6.1.132 #1 [ 3.907131] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 3.907784] Call Trace: [ 3.907925] <TASK> [ 3.908048] dump_stack_lvl+0x44/0x5c [ 3.908258] print_report+0x184/0x4be [ 3.909151] kasan_report+0xc5/0x100 [ 3.909539] kasan_check_range+0xf3/0x1a0 [ 3.909794] memcpy+0x1f/0x60 [ 3.909968] nla_put+0xa9/0xe0 [ 3.910147] tunnel_key_dump+0x945/0xba0 [ 3.911536] tcf_action_dump_1+0x1c1/0x340 [ 3.912436] tcf_action_dump+0x101/0x180 [ 3.912689] tcf_exts_dump+0x164/0x1e0 [ 3.912905] fw_dump+0x18b/0x2d0 [ 3.913483] tcf_fill_node+0x2ee/0x460 [ 3.914778] tfilter_notify+0xf4/0x180 [ 3.915208] tc_new_tfilter+0xd51/0x10d0 [ 3.918615] rtnetlink_rcv_msg+0x4a2/0x560 [ 3.919118] netlink_rcv_skb+0xcd/0x200 [ 3.919787] netlink_unicast+0x395/0x530 [ 3.921032] netlink_sendmsg+0x3d0/0x6d0 [ 3.921987] __sock_sendmsg+0x99/0xa0 [ 3.922220] __sys_sendto+0x1b7/0x240 [ 3.922682] __x64_sys_sendto+0x72/0x90 [ 3.922906] do_syscall_64+0x5e/0x90 [ 3.923814] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 3.924122] RIP: 0033:0x7e83eab84407 [ 3.924331] Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 faf [ 3.925330] RSP: 002b:00007ffff505e370 EFLAGS: 00000202 ORIG_RAX: 000000000000002c [ 3.925752] RAX: ffffffffffffffda RBX: 00007e83eaafa740 RCX: 00007e83eab84407 [ 3.926173] RDX: 00000000000001a8 RSI: 00007ffff505e3c0 RDI: 0000000000000003 [ 3.926587] RBP: 00007ffff505f460 R08: 00007e83eace1000 R09: 000000000000000c [ 3.926977] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffff505f3c0 [ 3.927367] R13: 00007ffff505f5c8 R14: 00007e83ead1b000 R15: 00005d4fbbe6dcb8 Fix these issues by enforing correct length condition in related policies. Fixes: 925d844696d9 ("netfilter: nft_tunnel: add support for geneve opts") Fixes: 4ece47787077 ("lwtunnel: add options setting and dumping for geneve") Fixes: 0ed5269f9e41 ("net/sched: add tunnel option support to act_tunnel_key") Fixes: 0a6e77784f49 ("net/sched: allow flower to match tunnel options") Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Xin Long <lucien.xin@gmail.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Link: https://patch.msgid.link/20250402165632.6958-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-03net: switch to netif_disable_lro in inetdev_initStanislav Fomichev
Cosmin reports the following deadlock: dump_stack_lvl+0x62/0x90 print_deadlock_bug+0x274/0x3b0 __lock_acquire+0x1229/0x2470 lock_acquire+0xb7/0x2b0 __mutex_lock+0xa6/0xd20 dev_disable_lro+0x20/0x80 inetdev_init+0x12f/0x1f0 inetdev_event+0x48b/0x870 notifier_call_chain+0x38/0xf0 netif_change_net_namespace+0x72e/0x9f0 do_setlink.isra.0+0xd5/0x1220 rtnl_newlink+0x7ea/0xb50 rtnetlink_rcv_msg+0x459/0x5e0 netlink_rcv_skb+0x54/0x100 netlink_unicast+0x193/0x270 netlink_sendmsg+0x204/0x450 Switch to netif_disable_lro which assumes the caller holds the instance lock. inetdev_init is called for blackhole device (which sw device and doesn't grab instance lock) and from REGISTER/UNREGISTER notifiers. We already hold the instance lock for REGISTER notifier during netns change and we'll soon hold the lock during other paths. Reviewed-by: Jakub Kicinski <kuba@kernel.org> Reported-by: Cosmin Ratiu <cratiu@nvidia.com> Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250401163452.622454-2-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-02tunnels: Accept PACKET_HOST in skb_tunnel_check_pmtu().Guillaume Nault
Because skb_tunnel_check_pmtu() doesn't handle PACKET_HOST packets, commit 30a92c9e3d6b ("openvswitch: Set the skbuff pkt_type for proper pmtud support.") forced skb->pkt_type to PACKET_OUTGOING for openvswitch packets that are sent using the OVS_ACTION_ATTR_OUTPUT action. This allowed such packets to invoke the iptunnel_pmtud_check_icmp() or iptunnel_pmtud_check_icmpv6() helpers and thus trigger PMTU update on the input device. However, this also broke other parts of PMTU discovery. Since these packets don't have the PACKET_HOST type anymore, they won't trigger the sending of ICMP Fragmentation Needed or Packet Too Big messages to remote hosts when oversized (see the skb_in->pkt_type condition in __icmp_send() for example). These two skb->pkt_type checks are therefore incompatible as one requires skb->pkt_type to be PACKET_HOST, while the other requires it to be anything but PACKET_HOST. It makes sense to not trigger ICMP messages for non-PACKET_HOST packets as these messages should be generated only for incoming l2-unicast packets. However there doesn't seem to be any reason for skb_tunnel_check_pmtu() to ignore PACKET_HOST packets. Allow both cases to work by allowing skb_tunnel_check_pmtu() to work on PACKET_HOST packets and not overriding skb->pkt_type in openvswitch anymore. Fixes: 30a92c9e3d6b ("openvswitch: Set the skbuff pkt_type for proper pmtud support.") Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets") Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Aaron Conole <aconole@redhat.com> Tested-by: Aaron Conole <aconole@redhat.com> Link: https://patch.msgid.link/eac941652b86fddf8909df9b3bf0d97bc9444793.1743208264.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-02udp: Fix memory accounting leak.Kuniyuki Iwashima
Matt Dowling reported a weird UDP memory usage issue. Under normal operation, the UDP memory usage reported in /proc/net/sockstat remains close to zero. However, it occasionally spiked to 524,288 pages and never dropped. Moreover, the value doubled when the application was terminated. Finally, it caused intermittent packet drops. We can reproduce the issue with the script below [0]: 1. /proc/net/sockstat reports 0 pages # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 0 2. Run the script till the report reaches 524,288 # python3 test.py & sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> PAGE_SHIFT 3. Kill the socket and confirm the number never drops # pkill python3 && sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 524288 4. (necessary since v6.0) Trigger proto_memory_pcpu_drain() # python3 test.py & sleep 1 && pkill python3 5. The number doubles # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 1048577 The application set INT_MAX to SO_RCVBUF, which triggered an integer overflow in udp_rmem_release(). When a socket is close()d, udp_destruct_common() purges its receive queue and sums up skb->truesize in the queue. This total is calculated and stored in a local unsigned integer variable. The total size is then passed to udp_rmem_release() to adjust memory accounting. However, because the function takes a signed integer argument, the total size can wrap around, causing an overflow. Then, the released amount is calculated as follows: 1) Add size to sk->sk_forward_alloc. 2) Round down sk->sk_forward_alloc to the nearest lower multiple of PAGE_SIZE and assign it to amount. 3) Subtract amount from sk->sk_forward_alloc. 4) Pass amount >> PAGE_SHIFT to __sk_mem_reduce_allocated(). When the issue occurred, the total in udp_destruct_common() was 2147484480 (INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release(). At 1) sk->sk_forward_alloc is changed from 3264 to -2147479552, and 2) sets -2147479552 to amount. 3) reverts the wraparound, so we don't see a warning in inet_sock_destruct(). However, udp_memory_allocated ends up doubling at 4). Since commit 3cd3399dd7a8 ("net: implement per-cpu reserves for memory_allocated"), memory usage no longer doubles immediately after a socket is close()d because __sk_mem_reduce_allocated() caches the amount in udp_memory_per_cpu_fw_alloc. However, the next time a UDP socket receives a packet, the subtraction takes effect, causing UDP memory usage to double. This issue makes further memory allocation fail once the socket's sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet drops. To prevent this issue, let's use unsigned int for the calculation and call sk_forward_alloc_add() only once for the small delta. Note that first_packet_length() also potentially has the same problem. [0]: from socket import * SO_RCVBUFFORCE = 33 INT_MAX = (2 ** 31) - 1 s = socket(AF_INET, SOCK_DGRAM) s.bind(('', 0)) s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX) c = socket(AF_INET, SOCK_DGRAM) c.connect(s.getsockname()) data = b'a' * 100 while True: c.send(data) Fixes: f970bd9e3a06 ("udp: implement memory accounting helpers") Reported-by: Matt Dowling <madowlin@amazon.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250401184501.67377-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-02udp: Fix multiple wraparounds of sk->sk_rmem_alloc.Kuniyuki Iwashima
__udp_enqueue_schedule_skb() has the following condition: if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) goto drop; sk->sk_rcvbuf is initialised by net.core.rmem_default and later can be configured by SO_RCVBUF, which is limited by net.core.rmem_max, or SO_RCVBUFFORCE. If we set INT_MAX to sk->sk_rcvbuf, the condition is always false as sk->sk_rmem_alloc is also signed int. Then, the size of the incoming skb is added to sk->sk_rmem_alloc unconditionally. This results in integer overflow (possibly multiple times) on sk->sk_rmem_alloc and allows a single socket to have skb up to net.core.udp_mem[1]. For example, if we set a large value to udp_mem[1] and INT_MAX to sk->sk_rcvbuf and flood packets to the socket, we can see multiple overflows: # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 7956736 <-- (7956736 << 12) bytes > INT_MAX * 15 ^- PAGE_SHIFT # ss -uam State Recv-Q ... UNCONN -1757018048 ... <-- flipping the sign repeatedly skmem:(r2537949248,rb2147483646,t0,tb212992,f1984,w0,o0,bl0,d0) Previously, we had a boundary check for INT_MAX, which was removed by commit 6a1f12dd85a8 ("udp: relax atomic operation on sk->sk_rmem_alloc"). A complete fix would be to revert it and cap the right operand by INT_MAX: rmem = atomic_add_return(size, &sk->sk_rmem_alloc); if (rmem > min(size + (unsigned int)sk->sk_rcvbuf, INT_MAX)) goto uncharge_drop; but we do not want to add the expensive atomic_add_return() back just for the corner case. Casting rmem to unsigned int prevents multiple wraparounds, but we still allow a single wraparound. # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> 12 # ss -uam State Recv-Q ... UNCONN -2147482816 ... <-- INT_MAX + 831 bytes skmem:(r2147484480,rb2147483646,t0,tb212992,f3264,w0,o0,bl0,d14468947) So, let's define rmem and rcvbuf as unsigned int and check skb->truesize only when rcvbuf is large enough to lower the overflow possibility. Note that we still have a small chance to see overflow if multiple skbs to the same socket are processed on different core at the same time and each size does not exceed the limit but the total size does. Note also that we must ignore skb->truesize for a small buffer as explained in commit 363dc73acacb ("udp: be less conservative with sock rmem accounting"). Fixes: 6a1f12dd85a8 ("udp: relax atomic operation on sk->sk_rmem_alloc") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250401184501.67377-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>