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git://git.open-mesh.org/linux-merge
Simon Wunderlich says:
====================
Here are some batman-adv bugfixes:
- Fix panic during interface removal in BATMAN V, by Andy Strohman
- Cleanup BATMAN V/ELP metric handling, by Sven Eckelmann (2 patches)
- Fix incorrect offset in batadv_tt_tvlv_ogm_handler_v1(),
by Remi Pommarel
* tag 'batadv-net-pullrequest-20250207' of git://git.open-mesh.org/linux-merge:
batman-adv: Fix incorrect offset in batadv_tt_tvlv_ogm_handler_v1()
batman-adv: Drop unmanaged ELP metric worker
batman-adv: Ignore neighbor throughput metrics in error case
batman-adv: fix panic during interface removal
====================
Link: https://patch.msgid.link/20250207095823.26043-1-sw@simonwunderlich.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can
Marc Kleine-Budde says:
====================
pull-request: can 2025-02-08
The first patch is by Reyders Morales and fixes a code example in the
CAN ISO15765-2 documentation.
The next patch is contributed by Alexander Hölzl and fixes sending of
J1939 messages with zero data length.
Fedor Pchelkin's patch for the ctucanfd driver adds a missing handling
for an skb allocation error.
Krzysztof Kozlowski contributes a patch for the c_can driver to fix
unbalanced runtime PM disable in error path.
The next patch is by Vincent Mailhol and fixes a NULL pointer
dereference on udev->serial in the etas_es58x driver.
The patch is by Robin van der Gracht and fixes the handling for an skb
allocation error.
* tag 'linux-can-fixes-for-6.14-20250208' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
can: rockchip: rkcanfd_handle_rx_fifo_overflow_int(): bail out if skb cannot be allocated
can: etas_es58x: fix potential NULL pointer dereference on udev->serial
can: c_can: fix unbalanced runtime PM disable in error path
can: ctucanfd: handle skb allocation failure
can: j1939: j1939_sk_send_loop(): fix unable to send messages with data length zero
Documentation/networking: fix basic node example document ISO 15765-2
====================
Link: https://patch.msgid.link/20250208115120.237274-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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igmp6_send() can be called without RTNL or RCU being held.
Extend RCU protection so that we can safely fetch the net pointer
and avoid a potential UAF.
Note that we no longer can use sock_alloc_send_skb() because
ipv6.igmp_sk uses GFP_KERNEL allocations which can sleep.
Instead use alloc_skb() and charge the net->ipv6.igmp_sk
socket under RCU protection.
Fixes: b8ad0cbc58f7 ("[NETNS][IPV6] mcast - handle several network namespace")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-9-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ndisc_send_skb() can be called without RTNL or RCU held.
Acquire rcu_read_lock() earlier, so that we can use dev_net_rcu()
and avoid a potential UAF.
Fixes: 1762f7e88eb3 ("[NETNS][IPV6] ndisc - make socket control per namespace")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-8-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ovs_vport_cmd_fill_info() can be called without RTNL or RCU.
Use RCU protection and dev_net_rcu() to avoid potential UAF.
Fixes: 9354d4520342 ("openvswitch: reliable interface indentification in port dumps")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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arp_xmit() can be called without RTNL or RCU protection.
Use RCU protection to avoid potential UAF.
Fixes: 29a26a568038 ("netfilter: Pass struct net into the netfilter hooks")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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__neigh_notify() can be called without RTNL or RCU protection.
Use RCU protection to avoid potential UAF.
Fixes: 426b5303eb43 ("[NETNS]: Modify the neighbour table code so it handles multiple network namespaces")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ndisc_alloc_skb() can be called without RTNL or RCU being held.
Add RCU protection to avoid possible UAF.
Fixes: de09334b9326 ("ndisc: Introduce ndisc_alloc_skb() helper.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ndisc_send_redirect() is called under RCU protection, not RTNL.
It must use dev_get_by_index_rcu() instead of __dev_get_by_index()
Fixes: 2f17becfbea5 ("vrf: check the original netdevice for generating redirect")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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length zero
The J1939 standard requires the transmission of messages of length 0.
For example proprietary messages are specified with a data length of 0
to 1785. The transmission of such messages is not possible. Sending
results in no error being returned but no corresponding can frame
being generated.
Enable the transmission of zero length J1939 messages. In order to
facilitate this two changes are necessary:
1) If the transmission of a new message is requested from user space
the message is segmented in j1939_sk_send_loop(). Let the segmentation
take into account zero length messages, do not terminate immediately,
queue the corresponding skb.
2) j1939_session_skb_get_by_offset() selects the next skb to transmit
for a session. Take into account that there might be zero length skbs
in the queue.
Signed-off-by: Alexander Hölzl <alexander.hoelzl@gmx.net>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250205174651.103238-1-alexander.hoelzl@gmx.net
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Cc: stable@vger.kernel.org
[mkl: commit message rephrased]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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This reverts commit dbae2b062824 ("net: skb: introduce and use a single
page frag cache"). The intended goal of such change was to counter a
performance regression introduced by commit 3226b158e67c ("net: avoid
32 x truesize under-estimation for tiny skbs").
Unfortunately, the blamed commit introduces another regression for the
virtio_net driver. Such a driver calls napi_alloc_skb() with a tiny
size, so that the whole head frag could fit a 512-byte block.
The single page frag cache uses a 1K fragment for such allocation, and
the additional overhead, under small UDP packets flood, makes the page
allocator a bottleneck.
Thanks to commit bf9f1baa279f ("net: add dedicated kmem_cache for
typical/small skb->head"), this revert does not re-introduce the
original regression. Actually, in the relevant test on top of this
revert, I measure a small but noticeable positive delta, just above
noise level.
The revert itself required some additional mangling due to the
introduction of the SKB_HEAD_ALIGN() helper and local lock infra in the
affected code.
Suggested-by: Eric Dumazet <edumazet@google.com>
Fixes: dbae2b062824 ("net: skb: introduce and use a single page frag cache")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/e649212fde9f0fdee23909ca0d14158d32bb7425.1738877290.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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rule->iifindex and rule->oifindex can be read without holding RTNL.
Add READ_ONCE()/WRITE_ONCE() annotations where needed.
Fixes: 32affa5578f0 ("fib: rules: no longer hold RTNL in fib_nl_dumprule()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250206083051.2494877-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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A call to rtnl_nets_destroy() is needed to release references taken on
netns put in rtnl_nets.
CC: stable@vger.kernel.org
Fixes: 636af13f213b ("rtnetlink: Register rtnl_dellink() and rtnl_setlink() with RTNL_FLAG_DOIT_PERNET_WIP.")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205221037.2474426-1-nicolas.dichtel@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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If an AX25 device is bound to a socket by setting the SO_BINDTODEVICE
socket option, a refcount leak will occur in ax25_release().
Commit 9fd75b66b8f6 ("ax25: Fix refcount leaks caused by ax25_cb_del()")
added decrement of device refcounts in ax25_release(). In order for that
to work correctly the refcounts must already be incremented when the
device is bound to the socket. An AX25 device can be bound to a socket
by either calling ax25_bind() or setting SO_BINDTODEVICE socket option.
In both cases the refcounts should be incremented, but in fact it is done
only in ax25_bind().
This bug leads to the following issue reported by Syzkaller:
================================================================
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 1 PID: 5932 at lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210 lib/refcount.c:31
Modules linked in:
CPU: 1 UID: 0 PID: 5932 Comm: syz-executor424 Not tainted 6.13.0-rc4-syzkaller-00110-g4099a71718b0 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x1ed/0x210 lib/refcount.c:31
Call Trace:
<TASK>
__refcount_dec include/linux/refcount.h:336 [inline]
refcount_dec include/linux/refcount.h:351 [inline]
ref_tracker_free+0x710/0x820 lib/ref_tracker.c:236
netdev_tracker_free include/linux/netdevice.h:4156 [inline]
netdev_put include/linux/netdevice.h:4173 [inline]
netdev_put include/linux/netdevice.h:4169 [inline]
ax25_release+0x33f/0xa10 net/ax25/af_ax25.c:1069
__sock_release+0xb0/0x270 net/socket.c:640
sock_close+0x1c/0x30 net/socket.c:1408
...
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
</TASK>
================================================================
Fix the implementation of ax25_setsockopt() by adding increment of
refcounts for the new device bound, and decrement of refcounts for
the old unbound device.
Fixes: 9fd75b66b8f6 ("ax25: Fix refcount leaks caused by ax25_cb_del()")
Reported-by: syzbot+33841dc6aa3e1d86b78a@syzkaller.appspotmail.com
Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru>
Link: https://patch.msgid.link/20250203091203.1744-1-m.masimov@mt-integration.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Fix the netlink type for hardware timestamp flags, which are represented
as a bitset of flags. Although only one flag is supported currently, the
correct netlink bitset type should be used instead of u32 to keep
consistency with other fields. Address this by adding a new named string
set description for the hwtstamp flag structure.
The code has been introduced in the current release so the uAPI change is
still okay.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Fixes: 6e9e2eed4f39 ("net: ethtool: Add support for tsconfig command to get/set hwtstamp config")
Link: https://patch.msgid.link/20250205110304.375086-1-kory.maincent@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Instead of grabbing rcu_read_lock() from ip6_input_finish(),
do it earlier in is caller, so that ip6_input() access
to dev_net() can be validated by LOCKDEP.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-13-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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icmp6_send() must acquire rcu_read_lock() sooner to ensure
the dev_net() call done from a safe context.
Other ICMPv6 uses of dev_net() seem safe, change them to
dev_net_rcu() to get LOCKDEP support to catch bugs.
Fixes: 9a43b709a230 ("[NETNS][IPV6] icmp6 - make icmpv6_socket per namespace")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-12-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ip6_default_advmss() needs rcu protection to make
sure the net structure it reads does not disappear.
Fixes: 5578689a4e3c ("[NETNS][IPV6] route6 - make route6 per namespace")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-11-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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__skb_flow_dissect() can be called from arbitrary contexts.
It must extend its RCU protection section to include
the call to dev_net(), which can become dev_net_rcu().
This makes sure the net structure can not disappear under us.
Fixes: 9b52e3f267a6 ("flow_dissector: handle no-skb use case")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-10-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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__icmp_send() must ensure rcu_read_lock() is held, as spotted
by Jakub.
Other ICMP uses of dev_net() seem safe, change them to dev_net_rcu()
to get LOCKDEP support.
Fixes: dde1bc0e6f86 ("[NETNS]: Add namespace for ICMP replying code.")
Closes: https://lore.kernel.org/netdev/20250203153633.46ce0337@kernel.org/
Reported-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-9-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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__ip_rt_update_pmtu() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: 2fbc6e89b2f1 ("ipv4: Update exception handling for multipath routes via same device")
Fixes: 1de6b15a434c ("Namespaceify min_pmtu sysctl")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-8-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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inet_select_addr() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: c4544c724322 ("[NETNS]: Process inet_select_addr inside a namespace.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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rt_is_expired() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: e84f84f27647 ("netns: place rt_genid into struct net")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ipv4_default_advmss() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: 2e9589ff809e ("ipv4: Namespaceify min_adv_mss sysctl knob")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Interestingly the recent kmemleak improvements allowed our CI to catch
a couple of percpu leaks addressed here.
We (mostly Jakub, to be accurate) are working to increase review
coverage over the net code-base tweaking the MAINTAINER entries.
Current release - regressions:
- core: harmonize tstats and dstats
- ipv6: fix dst refleaks in rpl, seg6 and ioam6 lwtunnels
- eth: tun: revert fix group permission check
- eth: stmmac: revert "specify hardware capability value when FIFO
size isn't specified"
Previous releases - regressions:
- udp: gso: do not drop small packets when PMTU reduces
- rxrpc: fix race in call state changing vs recvmsg()
- eth: ice: fix Rx data path for heavy 9k MTU traffic
- eth: vmxnet3: fix tx queue race condition with XDP
Previous releases - always broken:
- sched: pfifo_tail_enqueue: drop new packet when sch->limit == 0
- ethtool: ntuple: fix rss + ring_cookie check
- rxrpc: fix the rxrpc_connection attend queue handling
Misc:
- recognize Kuniyuki Iwashima as a maintainer"
* tag 'net-6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (34 commits)
Revert "net: stmmac: Specify hardware capability value when FIFO size isn't specified"
MAINTAINERS: add a sample ethtool section entry
MAINTAINERS: add entry for ethtool
rxrpc: Fix race in call state changing vs recvmsg()
rxrpc: Fix call state set to not include the SERVER_SECURING state
net: sched: Fix truncation of offloaded action statistics
tun: revert fix group permission check
selftests/tc-testing: Add a test case for qdisc_tree_reduce_backlog()
netem: Update sch->q.qlen before qdisc_tree_reduce_backlog()
selftests/tc-testing: Add a test case for pfifo_head_drop qdisc when limit==0
pfifo_tail_enqueue: Drop new packet when sch->limit == 0
selftests: mptcp: connect: -f: no reconnect
net: rose: lock the socket in rose_bind()
net: atlantic: fix warning during hot unplug
rxrpc: Fix the rxrpc_connection attend queue handling
net: harmonize tstats and dstats
selftests: drv-net: rss_ctx: don't fail reconfigure test if queue offset not supported
selftests: drv-net: rss_ctx: add missing cleanup in queue reconfigure
ethtool: ntuple: fix rss + ring_cookie check
ethtool: rss: fix hiding unsupported fields in dumps
...
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There's a race in between the rxrpc I/O thread recording the end of the
receive phase of a call and recvmsg() examining the state of the call to
determine whether it has completed.
The problem is that call->_state records the I/O thread's view of the call,
not the application's view (which may lag), so that alone is not
sufficient. To this end, the application also checks whether there is
anything left in call->recvmsg_queue for it to pick up. The call must be
in state RXRPC_CALL_COMPLETE and the recvmsg_queue empty for the call to be
considered fully complete.
In rxrpc_input_queue_data(), the latest skbuff is added to the queue and
then, if it was marked as LAST_PACKET, the state is advanced... But this
is two separate operations with no locking around them.
As a consequence, the lack of locking means that sendmsg() can jump into
the gap on a service call and attempt to send the reply - but then get
rejected because the I/O thread hasn't advanced the state yet.
Simply flipping the order in which things are done isn't an option as that
impacts the client side, causing the checks in rxrpc_kernel_check_life() as
to whether the call is still alive to race instead.
Fix this by moving the update of call->_state inside the skb queue
spinlocked section where the packet is queued on the I/O thread side.
rxrpc's recvmsg() will then automatically sync against this because it has
to take the call->recvmsg_queue spinlock in order to dequeue the last
packet.
rxrpc's sendmsg() doesn't need amending as the app shouldn't be calling it
to send a reply until recvmsg() indicates it has returned all of the
request.
Fixes: 93368b6bd58a ("rxrpc: Move call state changes from recvmsg to I/O thread")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20250204230558.712536-3-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The RXRPC_CALL_SERVER_SECURING state doesn't really belong with the other
states in the call's state set as the other states govern the call's Rx/Tx
phase transition and govern when packets can and can't be received or
transmitted. The "Securing" state doesn't actually govern the reception of
packets and would need to be split depending on whether or not we've
received the last packet yet (to mirror RECV_REQUEST/ACK_REQUEST).
The "Securing" state is more about whether or not we can start forwarding
packets to the application as recvmsg will need to decode them and the
decoding can't take place until the challenge/response exchange has
completed.
Fix this by removing the RXRPC_CALL_SERVER_SECURING state from the state
set and, instead, using a flag, RXRPC_CALL_CONN_CHALLENGING, to track
whether or not we can queue the call for reception by recvmsg() or notify
the kernel app that data is ready. In the event that we've already
received all the packets, the connection event handler will poke the app
layer in the appropriate manner.
Also there's a race whereby the app layer sees the last packet before rxrpc
has managed to end the rx phase and change the state to one amenable to
allowing a reply. Fix this by queuing the packet after calling
rxrpc_end_rx_phase().
Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20250204230558.712536-2-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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qdisc_tree_reduce_backlog() notifies parent qdisc only if child
qdisc becomes empty, therefore we need to reduce the backlog of the
child qdisc before calling it. Otherwise it would miss the opportunity
to call cops->qlen_notify(), in the case of DRR, it resulted in UAF
since DRR uses ->qlen_notify() to maintain its active list.
Fixes: f8d4bc455047 ("net/sched: netem: account for backlog updates from child qdisc")
Cc: Martin Ottens <martin.ottens@fau.de>
Reported-by: Mingi Cho <mincho@theori.io>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Link: https://patch.msgid.link/20250204005841.223511-4-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Expected behaviour:
In case we reach scheduler's limit, pfifo_tail_enqueue() will drop a
packet in scheduler's queue and decrease scheduler's qlen by one.
Then, pfifo_tail_enqueue() enqueue new packet and increase
scheduler's qlen by one. Finally, pfifo_tail_enqueue() return
`NET_XMIT_CN` status code.
Weird behaviour:
In case we set `sch->limit == 0` and trigger pfifo_tail_enqueue() on a
scheduler that has no packet, the 'drop a packet' step will do nothing.
This means the scheduler's qlen still has value equal 0.
Then, we continue to enqueue new packet and increase scheduler's qlen by
one. In summary, we can leverage pfifo_tail_enqueue() to increase qlen by
one and return `NET_XMIT_CN` status code.
The problem is:
Let's say we have two qdiscs: Qdisc_A and Qdisc_B.
- Qdisc_A's type must have '->graft()' function to create parent/child relationship.
Let's say Qdisc_A's type is `hfsc`. Enqueue packet to this qdisc will trigger `hfsc_enqueue`.
- Qdisc_B's type is pfifo_head_drop. Enqueue packet to this qdisc will trigger `pfifo_tail_enqueue`.
- Qdisc_B is configured to have `sch->limit == 0`.
- Qdisc_A is configured to route the enqueued's packet to Qdisc_B.
Enqueue packet through Qdisc_A will lead to:
- hfsc_enqueue(Qdisc_A) -> pfifo_tail_enqueue(Qdisc_B)
- Qdisc_B->q.qlen += 1
- pfifo_tail_enqueue() return `NET_XMIT_CN`
- hfsc_enqueue() check for `NET_XMIT_SUCCESS` and see `NET_XMIT_CN` => hfsc_enqueue() don't increase qlen of Qdisc_A.
The whole process lead to a situation where Qdisc_A->q.qlen == 0 and Qdisc_B->q.qlen == 1.
Replace 'hfsc' with other type (for example: 'drr') still lead to the same problem.
This violate the design where parent's qlen should equal to the sum of its childrens'qlen.
Bug impact: This issue can be used for user->kernel privilege escalation when it is reachable.
Fixes: 57dbb2d83d10 ("sched: add head drop fifo queue")
Reported-by: Quang Le <quanglex97@gmail.com>
Signed-off-by: Quang Le <quanglex97@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Link: https://patch.msgid.link/20250204005841.223511-2-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
syzbot reported a soft lockup in rose_loopback_timer(),
with a repro calling bind() from multiple threads.
rose_bind() must lock the socket to avoid this issue.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+7ff41b5215f0c534534e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/67a0f78d.050a0220.d7c5a.00a0.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/20250203170838.3521361-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The rxrpc_connection attend queue is never used because conn::attend_link
is never initialised and so is always NULL'd out and thus always appears to
be busy. This requires the following fix:
(1) Fix this the attend queue problem by initialising conn::attend_link.
And, consequently, two further fixes for things masked by the above bug:
(2) Fix rxrpc_input_conn_event() to handle being invoked with a NULL
sk_buff pointer - something that can now happen with the above change.
(3) Fix the RXRPC_SKB_MARK_SERVICE_CONN_SECURED message to carry a pointer
to the connection and a ref on it.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Fixes: f2cce89a074e ("rxrpc: Implement a mechanism to send an event notification to a connection")
Link: https://patch.msgid.link/20250203110307.7265-3-dhowells@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
After the blamed commits below, some UDP tunnel use dstats for
accounting. On the xmit path, all the UDP-base tunnels ends up
using iptunnel_xmit_stats() for stats accounting, and the latter
assumes the relevant (tunnel) network device uses tstats.
The end result is some 'funny' stat report for the mentioned UDP
tunnel, e.g. when no packet is actually dropped and a bunch of
packets are transmitted:
gnv2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue \
state UNKNOWN mode DEFAULT group default qlen 1000
link/ether ee:7d:09:87:90:ea brd ff:ff:ff:ff:ff:ff
RX: bytes packets errors dropped missed mcast
14916 23 0 15 0 0
TX: bytes packets errors dropped carrier collsns
0 1566 0 0 0 0
Address the issue ensuring the same binary layout for the overlapping
fields of dstats and tstats. While this solution is a bit hackish, is
smaller and with no performance pitfall compared to other alternatives
i.e. supporting both dstat and tstat in iptunnel_xmit_stats() or
reverting the blamed commit.
With time we should possibly move all the IP-based tunnel (and virtual
devices) to dstats.
Fixes: c77200c07491 ("bareudp: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Fixes: 6fa6de302246 ("geneve: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Fixes: be226352e8dc ("vxlan: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/2e1c444cf0f63ae472baff29862c4c869be17031.1738432804.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The info.flow_type is for RXFH commands, ntuple flow_type is inside
the flow spec. The check currently does nothing, as info.flow_type
is 0 (or even uninitialized by user space) for ETHTOOL_SRXCLSRLINS.
Fixes: 9e43ad7a1ede ("net: ethtool: only allow set_rxnfc with rss + ring_cookie if driver opts in")
Reviewed-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20250201013040.725123-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Commit ec6e57beaf8b ("ethtool: rss: don't report key if device
doesn't support it") intended to stop reporting key fields for
additional rss contexts if device has a global hashing key.
Later we added dump support and the filtering wasn't properly
added there. So we end up reporting the key fields in dumps
but not in dos:
# ./pyynl/cli.py --spec netlink/specs/ethtool.yaml --do rss-get \
--json '{"header": {"dev-index":2}, "context": 1 }'
{
"header": { ... },
"context": 1,
"indir": [0, 1, 2, 3, ...]]
}
# ./pyynl/cli.py --spec netlink/specs/ethtool.yaml --dump rss-get
[
... snip context 0 ...
{ "header": { ... },
"context": 1,
"indir": [0, 1, 2, 3, ...],
-> "input_xfrm": 255,
-> "hfunc": 1,
-> "hkey": "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
}
]
Hide these fields correctly.
The drivers/net/hw/rss_ctx.py selftest catches this when run on
a device with single key, already:
# Check| At /root/./ksft-net-drv/drivers/net/hw/rss_ctx.py, line 381, in test_rss_context_dump:
# Check| ksft_ne(set(data.get('hkey', [1])), {0}, "key is all zero")
# Check failed {0} == {0} key is all zero
not ok 8 rss_ctx.test_rss_context_dump
Fixes: f6122900f4e2 ("ethtool: rss: support dumping RSS contexts")
Reviewed-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20250201013040.725123-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Commit 4094871db1d6 ("udp: only do GSO if # of segs > 1") avoided GSO
for small packets. But the kernel currently dismisses GSO requests only
after checking MTU/PMTU on gso_size. This means any packets, regardless
of their payload sizes, could be dropped when PMTU becomes smaller than
requested gso_size. We encountered this issue in production and it
caused a reliability problem that new QUIC connection cannot be
established before PMTU cache expired, while non GSO sockets still
worked fine at the same time.
Ideally, do not check any GSO related constraints when payload size is
smaller than requested gso_size, and return EMSGSIZE instead of EINVAL
on MTU/PMTU check failure to be more specific on the error cause.
Fixes: 4094871db1d6 ("udp: only do GSO if # of segs > 1")
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Some lwtunnels have a dst cache for post-transformation dst.
If the packet destination did not change we may end up recording
a reference to the lwtunnel in its own cache, and the lwtunnel
state will never be freed.
Discovered by the ioam6.sh test, kmemleak was recently fixed
to catch per-cpu memory leaks. I'm not sure if rpl and seg6
can actually hit this, but in principle I don't see why not.
Fixes: 8cb3bf8bff3c ("ipv6: ioam: Add support for the ip6ip6 encapsulation")
Fixes: 6c8702c60b88 ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Fixes: a7a29f9c361f ("net: ipv6: add rpl sr tunnel")
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250130031519.2716843-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
dst_cache_get() gives us a reference, we need to release it.
Discovered by the ioam6.sh test, kmemleak was recently fixed
to catch per-cpu memory leaks.
Fixes: 985ec6f5e623 ("net: ipv6: rpl_iptunnel: mitigate 2-realloc issue")
Fixes: 40475b63761a ("net: ipv6: seg6_iptunnel: mitigate 2-realloc issue")
Fixes: dce525185bc9 ("net: ipv6: ioam6_iptunnel: mitigate 2-realloc issue")
Reviewed-by: Justin Iurman <justin.iurman@uliege.be>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250130031519.2716843-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Pull misc vfs cleanups from Al Viro:
"Two unrelated patches - one is a removal of long-obsolete include in
overlayfs (it used to need fs/internal.h, but the extern it wanted has
been moved back to include/linux/namei.h) and another introduces
convenience helper constructing struct qstr by a NUL-terminated
string"
* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
add a string-to-qstr constructor
fs/overlayfs/namei.c: get rid of include ../internal.h
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from IPSec, netfilter and Bluetooth.
Nothing really stands out, but as usual there's a slight concentration
of fixes for issues added in the last two weeks before the merge
window, and driver bugs from 6.13 which tend to get discovered upon
wider distribution.
Current release - regressions:
- net: revert RTNL changes in unregister_netdevice_many_notify()
- Bluetooth: fix possible infinite recursion of btusb_reset
- eth: adjust locking in some old drivers which protect their state
with spinlocks to avoid sleeping in atomic; core protects netdev
state with a mutex now
Previous releases - regressions:
- eth:
- mlx5e: make sure we pass node ID, not CPU ID to kvzalloc_node()
- bgmac: reduce max frame size to support just 1500 bytes; the
jumbo frame support would previously cause OOB writes, but now
fails outright
- mptcp: blackhole only if 1st SYN retrans w/o MPC is accepted, avoid
false detection of MPTCP blackholing
Previous releases - always broken:
- mptcp: handle fastopen disconnect correctly
- xfrm:
- make sure skb->sk is a full sock before accessing its fields
- fix taking a lock with preempt disabled for RT kernels
- usb: ipheth: improve safety of packet metadata parsing; prevent
potential OOB accesses
- eth: renesas: fix missing rtnl lock in suspend/resume path"
* tag 'net-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (88 commits)
MAINTAINERS: add Neal to TCP maintainers
net: revert RTNL changes in unregister_netdevice_many_notify()
net: hsr: fix fill_frame_info() regression vs VLAN packets
doc: mptcp: sysctl: blackhole_timeout is per-netns
mptcp: blackhole only if 1st SYN retrans w/o MPC is accepted
netfilter: nf_tables: reject mismatching sum of field_len with set key length
net: sh_eth: Fix missing rtnl lock in suspend/resume path
net: ravb: Fix missing rtnl lock in suspend/resume path
selftests/net: Add test for loading devbound XDP program in generic mode
net: xdp: Disallow attaching device-bound programs in generic mode
tcp: correct handling of extreme memory squeeze
bgmac: reduce max frame size to support just MTU 1500
vsock/test: Add test for connect() retries
vsock/test: Add test for UAF due to socket unbinding
vsock/test: Introduce vsock_connect_fd()
vsock/test: Introduce vsock_bind()
vsock: Allow retrying on connect() failure
vsock: Keep the binding until socket destruction
Bluetooth: L2CAP: accept zero as a special value for MTU auto-selection
Bluetooth: btnxpuart: Fix glitches seen in dual A2DP streaming
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following batch contains one Netfilter fix:
1) Reject mismatching sum of field_len with set key length which allows
to create a set without inconsistent pipapo rule width and set key
length.
* tag 'nf-25-01-30' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nf_tables: reject mismatching sum of field_len with set key length
====================
Link: https://patch.msgid.link/20250130113307.2327470-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
This patch reverts following changes:
83419b61d187 net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 2)
ae646f1a0bb9 net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 1)
cfa579f66656 net: no longer hold RTNL while calling flush_all_backlogs()
This caused issues in layers holding a private mutex:
cleanup_net()
rtnl_lock();
mutex_lock(subsystem_mutex);
unregister_netdevice();
rtnl_unlock(); // LOCKDEP violation
rtnl_lock();
I will revisit this in next cycle, opt-in for the new behavior
from safe contexts only.
Fixes: cfa579f66656 ("net: no longer hold RTNL while calling flush_all_backlogs()")
Fixes: ae646f1a0bb9 ("net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 1)")
Fixes: 83419b61d187 ("net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 2)")
Reported-by: syzbot+5b9196ecf74447172a9a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6789d55f.050a0220.20d369.004e.GAE@google.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250129142726.747726-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Stephan Wurm reported that my recent patch broke VLAN support.
Apparently skb->mac_len is not correct for VLAN traffic as
shown by debug traces [1].
Use instead pskb_may_pull() to make sure the expected header
is present in skb->head.
Many thanks to Stephan for his help.
[1]
kernel: skb len=170 headroom=2 headlen=170 tailroom=20
mac=(2,14) mac_len=14 net=(16,-1) trans=-1
shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0))
csum(0x0 start=0 offset=0 ip_summed=0 complete_sw=0 valid=0 level=0)
hash(0x0 sw=0 l4=0) proto=0x0000 pkttype=0 iif=0
priority=0x0 mark=0x0 alloc_cpu=0 vlan_all=0x0
encapsulation=0 inner(proto=0x0000, mac=0, net=0, trans=0)
kernel: dev name=prp0 feat=0x0000000000007000
kernel: sk family=17 type=3 proto=0
kernel: skb headroom: 00000000: 74 00
kernel: skb linear: 00000000: 01 0c cd 01 00 01 00 d0 93 53 9c cb 81 00 80 00
kernel: skb linear: 00000010: 88 b8 00 01 00 98 00 00 00 00 61 81 8d 80 16 52
kernel: skb linear: 00000020: 45 47 44 4e 43 54 52 4c 2f 4c 4c 4e 30 24 47 4f
kernel: skb linear: 00000030: 24 47 6f 43 62 81 01 14 82 16 52 45 47 44 4e 43
kernel: skb linear: 00000040: 54 52 4c 2f 4c 4c 4e 30 24 44 73 47 6f 6f 73 65
kernel: skb linear: 00000050: 83 07 47 6f 49 64 65 6e 74 84 08 67 8d f5 93 7e
kernel: skb linear: 00000060: 76 c8 00 85 01 01 86 01 00 87 01 00 88 01 01 89
kernel: skb linear: 00000070: 01 00 8a 01 02 ab 33 a2 15 83 01 00 84 03 03 00
kernel: skb linear: 00000080: 00 91 08 67 8d f5 92 77 4b c6 1f 83 01 00 a2 1a
kernel: skb linear: 00000090: a2 06 85 01 00 83 01 00 84 03 03 00 00 91 08 67
kernel: skb linear: 000000a0: 8d f5 92 77 4b c6 1f 83 01 00
kernel: skb tailroom: 00000000: 80 18 02 00 fe 4e 00 00 01 01 08 0a 4f fd 5e d1
kernel: skb tailroom: 00000010: 4f fd 5e cd
Fixes: b9653d19e556 ("net: hsr: avoid potential out-of-bound access in fill_frame_info()")
Reported-by: Stephan Wurm <stephan.wurm@a-eberle.de>
Tested-by: Stephan Wurm <stephan.wurm@a-eberle.de>
Closes: https://lore.kernel.org/netdev/Z4o_UC0HweBHJ_cw@PC-LX-SteWu/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250129130007.644084-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The Fixes commit mentioned this:
> An MPTCP firewall blackhole can be detected if the following SYN
> retransmission after a fallback to "plain" TCP is accepted.
But in fact, this blackhole was detected if any following SYN
retransmissions after a fallback to TCP was accepted.
That's because 'mptcp_subflow_early_fallback()' will set 'request_mptcp'
to 0, and 'mpc_drop' will never be reset to 0 after.
This is an issue, because some not so unusual situations might cause the
kernel to detect a false-positive blackhole, e.g. a client trying to
connect to a server while the network is not ready yet, causing a few
SYN retransmissions, before reaching the end server.
Fixes: 27069e7cb3d1 ("mptcp: disable active MPTCP in case of blackhole")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
The field length description provides the length of each separated key
field in the concatenation, each field gets rounded up to 32-bits to
calculate the pipapo rule width from pipapo_init(). The set key length
provides the total size of the key aligned to 32-bits.
Register-based arithmetics still allows for combining mismatching set
key length and field length description, eg. set key length 10 and field
description [ 5, 4 ] leading to pipapo width of 12.
Cc: stable@vger.kernel.org
Fixes: 3ce67e3793f4 ("netfilter: nf_tables: do not allow mismatch field size and set key length")
Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth
Luiz Augusto von Dentz says:
====================
bluetooth pull request for net:
- btusb: mediatek: Add locks for usb_driver_claim_interface()
- L2CAP: accept zero as a special value for MTU auto-selection
- btusb: Fix possible infinite recursion of btusb_reset
- Add ABI doc for sysfs reset
- btnxpuart: Fix glitches seen in dual A2DP streaming
* tag 'for-net-2025-01-29' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
Bluetooth: L2CAP: accept zero as a special value for MTU auto-selection
Bluetooth: btnxpuart: Fix glitches seen in dual A2DP streaming
Bluetooth: Add ABI doc for sysfs reset
Bluetooth: Fix possible infinite recursion of btusb_reset
Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface()
====================
Link: https://patch.msgid.link/20250129210057.1318963-1-luiz.dentz@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Device-bound programs are used to support RX metadata kfuncs. These
kfuncs are driver-specific and rely on the driver context to read the
metadata. This means they can't work in generic XDP mode. However, there
is no check to disallow such programs from being attached in generic
mode, in which case the metadata kfuncs will be called in an invalid
context, leading to crashes.
Fix this by adding a check to disallow attaching device-bound programs
in generic mode.
Fixes: 2b3486bc2d23 ("bpf: Introduce device-bound XDP programs")
Reported-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de>
Closes: https://lore.kernel.org/r/dae862ec-43b5-41a0-8edf-46c59071cdda@hetzner-cloud.de
Tested-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250127131344.238147-1-toke@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Testing with iperf3 using the "pasta" protocol splicer has revealed
a problem in the way tcp handles window advertising in extreme memory
squeeze situations.
Under memory pressure, a socket endpoint may temporarily advertise
a zero-sized window, but this is not stored as part of the socket data.
The reasoning behind this is that it is considered a temporary setting
which shouldn't influence any further calculations.
However, if we happen to stall at an unfortunate value of the current
window size, the algorithm selecting a new value will consistently fail
to advertise a non-zero window once we have freed up enough memory.
This means that this side's notion of the current window size is
different from the one last advertised to the peer, causing the latter
to not send any data to resolve the sitution.
The problem occurs on the iperf3 server side, and the socket in question
is a completely regular socket with the default settings for the
fedora40 kernel. We do not use SO_PEEK or SO_RCVBUF on the socket.
The following excerpt of a logging session, with own comments added,
shows more in detail what is happening:
// tcp_v4_rcv(->)
// tcp_rcv_established(->)
[5201<->39222]: ==== Activating log @ net/ipv4/tcp_input.c/tcp_data_queue()/5257 ====
[5201<->39222]: tcp_data_queue(->)
[5201<->39222]: DROPPING skb [265600160..265665640], reason: SKB_DROP_REASON_PROTO_MEM
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 259909392->260034360 (124968), unread 5565800, qlen 85, ofoq 0]
[OFO queue: gap: 65480, len: 0]
[5201<->39222]: tcp_data_queue(<-)
[5201<->39222]: __tcp_transmit_skb(->)
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: tcp_select_window(->)
[5201<->39222]: (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_NOMEM) ? --> TRUE
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
returning 0
[5201<->39222]: tcp_select_window(<-)
[5201<->39222]: ADVERTISING WIN 0, ACK_SEQ: 265600160
[5201<->39222]: [__tcp_transmit_skb(<-)
[5201<->39222]: tcp_rcv_established(<-)
[5201<->39222]: tcp_v4_rcv(<-)
// Receive queue is at 85 buffers and we are out of memory.
// We drop the incoming buffer, although it is in sequence, and decide
// to send an advertisement with a window of zero.
// We don't update tp->rcv_wnd and tp->rcv_wup accordingly, which means
// we unconditionally shrink the window.
[5201<->39222]: tcp_recvmsg_locked(->)
[5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160
[5201<->39222]: [new_win = 0, win_now = 131184, 2 * win_now = 262368]
[5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0]
[5201<->39222]: NOT calling tcp_send_ack()
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: __tcp_cleanup_rbuf(<-)
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 260040464->260040464 (0), unread 5559696, qlen 85, ofoq 0]
returning 6104 bytes
[5201<->39222]: tcp_recvmsg_locked(<-)
// After each read, the algorithm for calculating the new receive
// window in __tcp_cleanup_rbuf() finds it is too small to advertise
// or to update tp->rcv_wnd.
// Meanwhile, the peer thinks the window is zero, and will not send
// any more data to trigger an update from the interrupt mode side.
[5201<->39222]: tcp_recvmsg_locked(->)
[5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160
[5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_now = 262368]
[5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0]
[5201<->39222]: NOT calling tcp_send_ack()
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: __tcp_cleanup_rbuf(<-)
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 260099840->260171536 (71696), unread 5428624, qlen 83, ofoq 0]
returning 131072 bytes
[5201<->39222]: tcp_recvmsg_locked(<-)
// The above pattern repeats again and again, since nothing changes
// between the reads.
[...]
[5201<->39222]: tcp_recvmsg_locked(->)
[5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160
[5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_now = 262368]
[5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0]
[5201<->39222]: NOT calling tcp_send_ack()
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: __tcp_cleanup_rbuf(<-)
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 265600160->265600160 (0), unread 0, qlen 0, ofoq 0]
returning 54672 bytes
[5201<->39222]: tcp_recvmsg_locked(<-)
// The receive queue is empty, but no new advertisement has been sent.
// The peer still thinks the receive window is zero, and sends nothing.
// We have ended up in a deadlock situation.
Note that well behaved endpoints will send win0 probes, so the problem
will not occur.
Furthermore, we have observed that in these situations this side may
send out an updated 'th->ack_seq´ which is not stored in tp->rcv_wup
as it should be. Backing ack_seq seems to be harmless, but is of
course still wrong from a protocol viewpoint.
We fix this by updating the socket state correctly when a packet has
been dropped because of memory exhaustion and we have to advertize
a zero window.
Further testing shows that the connection recovers neatly from the
squeeze situation, and traffic can continue indefinitely.
Fixes: e2142825c120 ("net: tcp: send zero-window ACK when no memory")
Cc: Menglong Dong <menglong8.dong@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20250127231304.1465565-1-jmaloy@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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sk_err is set when a (connectible) connect() fails. Effectively, this makes
an otherwise still healthy SS_UNCONNECTED socket impossible to use for any
subsequent connection attempts.
Clear sk_err upon trying to establish a connection.
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250128-vsock-transport-vs-autobind-v3-2-1cf57065b770@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Preserve sockets bindings; this includes both resulting from an explicit
bind() and those implicitly bound through autobind during connect().
Prevents socket unbinding during a transport reassignment, which fixes a
use-after-free:
1. vsock_create() (refcnt=1) calls vsock_insert_unbound() (refcnt=2)
2. transport->release() calls vsock_remove_bound() without checking if
sk was bound and moved to bound list (refcnt=1)
3. vsock_bind() assumes sk is in unbound list and before
__vsock_insert_bound(vsock_bound_sockets()) calls
__vsock_remove_bound() which does:
list_del_init(&vsk->bound_table); // nop
sock_put(&vsk->sk); // refcnt=0
BUG: KASAN: slab-use-after-free in __vsock_bind+0x62e/0x730
Read of size 4 at addr ffff88816b46a74c by task a.out/2057
dump_stack_lvl+0x68/0x90
print_report+0x174/0x4f6
kasan_report+0xb9/0x190
__vsock_bind+0x62e/0x730
vsock_bind+0x97/0xe0
__sys_bind+0x154/0x1f0
__x64_sys_bind+0x6e/0xb0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Allocated by task 2057:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
__kasan_slab_alloc+0x85/0x90
kmem_cache_alloc_noprof+0x131/0x450
sk_prot_alloc+0x5b/0x220
sk_alloc+0x2c/0x870
__vsock_create.constprop.0+0x2e/0xb60
vsock_create+0xe4/0x420
__sock_create+0x241/0x650
__sys_socket+0xf2/0x1a0
__x64_sys_socket+0x6e/0xb0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 2057:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
kasan_save_free_info+0x37/0x60
__kasan_slab_free+0x4b/0x70
kmem_cache_free+0x1a1/0x590
__sk_destruct+0x388/0x5a0
__vsock_bind+0x5e1/0x730
vsock_bind+0x97/0xe0
__sys_bind+0x154/0x1f0
__x64_sys_bind+0x6e/0xb0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 7 PID: 2057 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150
RIP: 0010:refcount_warn_saturate+0xce/0x150
__vsock_bind+0x66d/0x730
vsock_bind+0x97/0xe0
__sys_bind+0x154/0x1f0
__x64_sys_bind+0x6e/0xb0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
refcount_t: underflow; use-after-free.
WARNING: CPU: 7 PID: 2057 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150
RIP: 0010:refcount_warn_saturate+0xee/0x150
vsock_remove_bound+0x187/0x1e0
__vsock_release+0x383/0x4a0
vsock_release+0x90/0x120
__sock_release+0xa3/0x250
sock_close+0x14/0x20
__fput+0x359/0xa80
task_work_run+0x107/0x1d0
do_exit+0x847/0x2560
do_group_exit+0xb8/0x250
__x64_sys_exit_group+0x3a/0x50
x64_sys_call+0xfec/0x14f0
do_syscall_64+0x93/0x1b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250128-vsock-transport-vs-autobind-v3-1-1cf57065b770@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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One of the possible ways to enable the input MTU auto-selection for L2CAP
connections is supposed to be through passing a special "0" value for it
as a socket option. Commit [1] added one of those into avdtp. However, it
simply wouldn't work because the kernel still treats the specified value
as invalid and denies the setting attempt. Recorded BlueZ logs include the
following:
bluetoothd[496]: profiles/audio/avdtp.c:l2cap_connect() setsockopt(L2CAP_OPTIONS): Invalid argument (22)
[1]: https://github.com/bluez/bluez/commit/ae5be371a9f53fed33d2b34748a95a5498fd4b77
Found by Linux Verification Center (linuxtesting.org).
Fixes: 4b6e228e297b ("Bluetooth: Auto tune if input MTU is set to 0")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
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