linux-stable.git/include/net, branch v6.14.3 Linux kernel stable tree sctp: detect and prevent references to a freed transport in sendmsg 2025-04-20T08:23:09+00:00 Ricardo Cañuelo Navarro rcn@igalia.com 2025-04-04T14:53:21+00:00 2e5068b7e0ae0a54f6cfd03a2f80977da657f1ee commit f1a69a940de58b16e8249dff26f74c8cc59b32be upstream. sctp_sendmsg() re-uses associations and transports when possible by doing a lookup based on the socket endpoint and the message destination address, and then sctp_sendmsg_to_asoc() sets the selected transport in all the message chunks to be sent. There's a possible race condition if another thread triggers the removal of that selected transport, for instance, by explicitly unbinding an address with setsockopt(SCTP_SOCKOPT_BINDX_REM), after the chunks have been set up and before the message is sent. This can happen if the send buffer is full, during the period when the sender thread temporarily releases the socket lock in sctp_wait_for_sndbuf(). This causes the access to the transport data in sctp_outq_select_transport(), when the association outqueue is flushed, to result in a use-after-free read. This change avoids this scenario by having sctp_transport_free() signal the freeing of the transport, tagging it as "dead". In order to do this, the patch restores the "dead" bit in struct sctp_transport, which was removed in commit 47faa1e4c50e ("sctp: remove the dead field of sctp_transport"). Then, in the scenario where the sender thread has released the socket lock in sctp_wait_for_sndbuf(), the bit is checked again after re-acquiring the socket lock to detect the deletion. This is done while holding a reference to the transport to prevent it from being freed in the process. If the transport was deleted while the socket lock was relinquished, sctp_sendmsg_to_asoc() will return -EAGAIN to let userspace retry the send. The bug was found by a private syzbot instance (see the error report [1] and the C reproducer that triggers it [2]). Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport.txt [1] Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport__repro.c [2] Cc: stable@vger.kernel.org Fixes: df132eff4638 ("sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peer") Suggested-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com> Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20250404-kasan_slab-use-after-free_read_in_sctp_outq_select_transport__20250404-v1-1-5ce4a0b78ef2@igalia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f1a69a940de58b16e8249dff26f74c8cc59b32be upstream.

sctp_sendmsg() re-uses associations and transports when possible by
doing a lookup based on the socket endpoint and the message destination
address, and then sctp_sendmsg_to_asoc() sets the selected transport in
all the message chunks to be sent.

There's a possible race condition if another thread triggers the removal
of that selected transport, for instance, by explicitly unbinding an
address with setsockopt(SCTP_SOCKOPT_BINDX_REM), after the chunks have
been set up and before the message is sent. This can happen if the send
buffer is full, during the period when the sender thread temporarily
releases the socket lock in sctp_wait_for_sndbuf().

This causes the access to the transport data in
sctp_outq_select_transport(), when the association outqueue is flushed,
to result in a use-after-free read.

This change avoids this scenario by having sctp_transport_free() signal
the freeing of the transport, tagging it as "dead". In order to do this,
the patch restores the "dead" bit in struct sctp_transport, which was
removed in
commit 47faa1e4c50e ("sctp: remove the dead field of sctp_transport").

Then, in the scenario where the sender thread has released the socket
lock in sctp_wait_for_sndbuf(), the bit is checked again after
re-acquiring the socket lock to detect the deletion. This is done while
holding a reference to the transport to prevent it from being freed in
the process.

If the transport was deleted while the socket lock was relinquished,
sctp_sendmsg_to_asoc() will return -EAGAIN to let userspace retry the
send.

The bug was found by a private syzbot instance (see the error report [1]
and the C reproducer that triggers it [2]).

Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport.txt [1]
Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport__repro.c [2]
Cc: stable@vger.kernel.org
Fixes: df132eff4638 ("sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peer")
Suggested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20250404-kasan_slab-use-after-free_read_in_sctp_outq_select_transport__20250404-v1-1-5ce4a0b78ef2@igalia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: Fix null-ptr-deref by sock_lock_init_class_and_name() and rmmod. 2025-04-20T08:23:07+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2025-04-07T16:33:11+00:00 2155802d3313d7b8365935c6b8d6edc0ddd7eb94 commit 0bb2f7a1ad1f11d861f58e5ee5051c8974ff9569 upstream. When I ran the repro [0] and waited a few seconds, I observed two LOCKDEP splats: a warning immediately followed by a null-ptr-deref. [1] Reproduction Steps: 1) Mount CIFS 2) Add an iptables rule to drop incoming FIN packets for CIFS 3) Unmount CIFS 4) Unload the CIFS module 5) Remove the iptables rule At step 3), the CIFS module calls sock_release() for the underlying TCP socket, and it returns quickly. However, the socket remains in FIN_WAIT_1 because incoming FIN packets are dropped. At this point, the module's refcnt is 0 while the socket is still alive, so the following rmmod command succeeds. # ss -tan State Recv-Q Send-Q Local Address:Port Peer Address:Port FIN-WAIT-1 0 477 10.0.2.15:51062 10.0.0.137:445 # lsmod | grep cifs cifs 1159168 0 This highlights a discrepancy between the lifetime of the CIFS module and the underlying TCP socket. Even after CIFS calls sock_release() and it returns, the TCP socket does not die immediately in order to close the connection gracefully. While this is generally fine, it causes an issue with LOCKDEP because CIFS assigns a different lock class to the TCP socket's sk->sk_lock using sock_lock_init_class_and_name(). Once an incoming packet is processed for the socket or a timer fires, sk->sk_lock is acquired. Then, LOCKDEP checks the lock context in check_wait_context(), where hlock_class() is called to retrieve the lock class. However, since the module has already been unloaded, hlock_class() logs a warning and returns NULL, triggering the null-ptr-deref. If LOCKDEP is enabled, we must ensure that a module calling sock_lock_init_class_and_name() (CIFS, NFS, etc) cannot be unloaded while such a socket is still alive to prevent this issue. Let's hold the module reference in sock_lock_init_class_and_name() and release it when the socket is freed in sk_prot_free(). Note that sock_lock_init() clears sk->sk_owner for svc_create_socket() that calls sock_lock_init_class_and_name() for a listening socket, which clones a socket by sk_clone_lock() without GFP_ZERO. [0]: CIFS_SERVER="10.0.0.137" CIFS_PATH="//${CIFS_SERVER}/Users/Administrator/Desktop/CIFS_TEST" DEV="enp0s3" CRED="/root/WindowsCredential.txt" MNT=$(mktemp -d /tmp/XXXXXX) mount -t cifs ${CIFS_PATH} ${MNT} -o vers=3.0,credentials=${CRED},cache=none,echo_interval=1 iptables -A INPUT -s ${CIFS_SERVER} -j DROP for i in $(seq 10); do umount ${MNT} rmmod cifs sleep 1 done rm -r ${MNT} iptables -D INPUT -s ${CIFS_SERVER} -j DROP [1]: DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 10 PID: 0 at kernel/locking/lockdep.c:234 hlock_class (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223) Modules linked in: cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs] CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Not tainted 6.14.0 #36 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:hlock_class (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223) ... Call Trace: <IRQ> __lock_acquire (kernel/locking/lockdep.c:4853 kernel/locking/lockdep.c:5178) lock_acquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816) _raw_spin_lock_nested (kernel/locking/spinlock.c:379) tcp_v4_rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcp_ipv4.c:2350) ... BUG: kernel NULL pointer dereference, address: 00000000000000c4 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Tainted: G W 6.14.0 #36 Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:__lock_acquire (kernel/locking/lockdep.c:4852 kernel/locking/lockdep.c:5178) Code: 15 41 09 c7 41 8b 44 24 20 25 ff 1f 00 00 41 09 c7 8b 84 24 a0 00 00 00 45 89 7c 24 20 41 89 44 24 24 e8 e1 bc ff ff 4c 89 e7 <44> 0f b6 b8 c4 00 00 00 e8 d1 bc ff ff 0f b6 80 c5 00 00 00 88 44 RSP: 0018:ffa0000000468a10 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ff1100010091cc38 RCX: 0000000000000027 RDX: ff1100081f09ca48 RSI: 0000000000000001 RDI: ff1100010091cc88 RBP: ff1100010091c200 R08: ff1100083fe6e228 R09: 00000000ffffbfff R10: ff1100081eca0000 R11: ff1100083fe10dc0 R12: ff1100010091cc88 R13: 0000000000000001 R14: 0000000000000000 R15: 00000000000424b1 FS: 0000000000000000(0000) GS:ff1100081f080000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c4 CR3: 0000000002c4a003 CR4: 0000000000771ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> lock_acquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816) _raw_spin_lock_nested (kernel/locking/spinlock.c:379) tcp_v4_rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcp_ipv4.c:2350) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205 (discriminator 1)) ip_local_deliver_finish (./include/linux/rcupdate.h:878 net/ipv4/ip_input.c:234) ip_sublist_rcv_finish (net/ipv4/ip_input.c:576) ip_list_rcv_finish (net/ipv4/ip_input.c:628) ip_list_rcv (net/ipv4/ip_input.c:670) __netif_receive_skb_list_core (net/core/dev.c:5939 net/core/dev.c:5986) netif_receive_skb_list_internal (net/core/dev.c:6040 net/core/dev.c:6129) napi_complete_done (./include/linux/list.h:37 ./include/net/gro.h:519 ./include/net/gro.h:514 net/core/dev.c:6496) e1000_clean (drivers/net/ethernet/intel/e1000/e1000_main.c:3815) __napi_poll.constprop.0 (net/core/dev.c:7191) net_rx_action (net/core/dev.c:7262 net/core/dev.c:7382) handle_softirqs (kernel/softirq.c:561) __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662) irq_exit_rcu (kernel/softirq.c:680) common_interrupt (arch/x86/kernel/irq.c:280 (discriminator 14)) </IRQ> <TASK> asm_common_interrupt (./arch/x86/include/asm/idtentry.h:693) RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:744) Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d c3 2b 15 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 RSP: 0018:ffa00000000ffee8 EFLAGS: 00000202 RAX: 000000000000640b RBX: ff1100010091c200 RCX: 0000000000061aa4 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff812f30c5 RBP: 000000000000000a R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ? do_idle (kernel/sched/idle.c:186 kernel/sched/idle.c:325) default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) do_idle (kernel/sched/idle.c:186 kernel/sched/idle.c:325) cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1)) start_secondary (arch/x86/kernel/smpboot.c:315) common_startup_64 (arch/x86/kernel/head_64.S:421) </TASK> Modules linked in: cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs] CR2: 00000000000000c4 Fixes: ed07536ed673 ("[PATCH] lockdep: annotate nfs/nfsd in-kernel sockets") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250407163313.22682-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0bb2f7a1ad1f11d861f58e5ee5051c8974ff9569 upstream.

When I ran the repro [0] and waited a few seconds, I observed two
LOCKDEP splats: a warning immediately followed by a null-ptr-deref. [1]

Reproduction Steps:

  1) Mount CIFS
  2) Add an iptables rule to drop incoming FIN packets for CIFS
  3) Unmount CIFS
  4) Unload the CIFS module
  5) Remove the iptables rule

At step 3), the CIFS module calls sock_release() for the underlying
TCP socket, and it returns quickly.  However, the socket remains in
FIN_WAIT_1 because incoming FIN packets are dropped.

At this point, the module's refcnt is 0 while the socket is still
alive, so the following rmmod command succeeds.

  # ss -tan
  State      Recv-Q Send-Q Local Address:Port  Peer Address:Port
  FIN-WAIT-1 0      477        10.0.2.15:51062   10.0.0.137:445

  # lsmod | grep cifs
  cifs                 1159168  0

This highlights a discrepancy between the lifetime of the CIFS module
and the underlying TCP socket.  Even after CIFS calls sock_release()
and it returns, the TCP socket does not die immediately in order to
close the connection gracefully.

While this is generally fine, it causes an issue with LOCKDEP because
CIFS assigns a different lock class to the TCP socket's sk->sk_lock
using sock_lock_init_class_and_name().

Once an incoming packet is processed for the socket or a timer fires,
sk->sk_lock is acquired.

Then, LOCKDEP checks the lock context in check_wait_context(), where
hlock_class() is called to retrieve the lock class.  However, since
the module has already been unloaded, hlock_class() logs a warning
and returns NULL, triggering the null-ptr-deref.

If LOCKDEP is enabled, we must ensure that a module calling
sock_lock_init_class_and_name() (CIFS, NFS, etc) cannot be unloaded
while such a socket is still alive to prevent this issue.

Let's hold the module reference in sock_lock_init_class_and_name()
and release it when the socket is freed in sk_prot_free().

Note that sock_lock_init() clears sk->sk_owner for svc_create_socket()
that calls sock_lock_init_class_and_name() for a listening socket,
which clones a socket by sk_clone_lock() without GFP_ZERO.

[0]:
CIFS_SERVER="10.0.0.137"
CIFS_PATH="//${CIFS_SERVER}/Users/Administrator/Desktop/CIFS_TEST"
DEV="enp0s3"
CRED="/root/WindowsCredential.txt"

MNT=$(mktemp -d /tmp/XXXXXX)
mount -t cifs ${CIFS_PATH} ${MNT} -o vers=3.0,credentials=${CRED},cache=none,echo_interval=1

iptables -A INPUT -s ${CIFS_SERVER} -j DROP

for i in $(seq 10);
do
    umount ${MNT}
    rmmod cifs
    sleep 1
done

rm -r ${MNT}

iptables -D INPUT -s ${CIFS_SERVER} -j DROP

[1]:
DEBUG_LOCKS_WARN_ON(1)
WARNING: CPU: 10 PID: 0 at kernel/locking/lockdep.c:234 hlock_class (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223)
Modules linked in: cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs]
CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Not tainted 6.14.0 #36
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:hlock_class (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223)
...
Call Trace:
 <IRQ>
 __lock_acquire (kernel/locking/lockdep.c:4853 kernel/locking/lockdep.c:5178)
 lock_acquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816)
 _raw_spin_lock_nested (kernel/locking/spinlock.c:379)
 tcp_v4_rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcp_ipv4.c:2350)
...

BUG: kernel NULL pointer dereference, address: 00000000000000c4
 PF: supervisor read access in kernel mode
 PF: error_code(0x0000) - not-present page
PGD 0
Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Tainted: G        W          6.14.0 #36
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:__lock_acquire (kernel/locking/lockdep.c:4852 kernel/locking/lockdep.c:5178)
Code: 15 41 09 c7 41 8b 44 24 20 25 ff 1f 00 00 41 09 c7 8b 84 24 a0 00 00 00 45 89 7c 24 20 41 89 44 24 24 e8 e1 bc ff ff 4c 89 e7 <44> 0f b6 b8 c4 00 00 00 e8 d1 bc ff ff 0f b6 80 c5 00 00 00 88 44
RSP: 0018:ffa0000000468a10 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ff1100010091cc38 RCX: 0000000000000027
RDX: ff1100081f09ca48 RSI: 0000000000000001 RDI: ff1100010091cc88
RBP: ff1100010091c200 R08: ff1100083fe6e228 R09: 00000000ffffbfff
R10: ff1100081eca0000 R11: ff1100083fe10dc0 R12: ff1100010091cc88
R13: 0000000000000001 R14: 0000000000000000 R15: 00000000000424b1
FS:  0000000000000000(0000) GS:ff1100081f080000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000c4 CR3: 0000000002c4a003 CR4: 0000000000771ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <IRQ>
 lock_acquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816)
 _raw_spin_lock_nested (kernel/locking/spinlock.c:379)
 tcp_v4_rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcp_ipv4.c:2350)
 ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205 (discriminator 1))
 ip_local_deliver_finish (./include/linux/rcupdate.h:878 net/ipv4/ip_input.c:234)
 ip_sublist_rcv_finish (net/ipv4/ip_input.c:576)
 ip_list_rcv_finish (net/ipv4/ip_input.c:628)
 ip_list_rcv (net/ipv4/ip_input.c:670)
 __netif_receive_skb_list_core (net/core/dev.c:5939 net/core/dev.c:5986)
 netif_receive_skb_list_internal (net/core/dev.c:6040 net/core/dev.c:6129)
 napi_complete_done (./include/linux/list.h:37 ./include/net/gro.h:519 ./include/net/gro.h:514 net/core/dev.c:6496)
 e1000_clean (drivers/net/ethernet/intel/e1000/e1000_main.c:3815)
 __napi_poll.constprop.0 (net/core/dev.c:7191)
 net_rx_action (net/core/dev.c:7262 net/core/dev.c:7382)
 handle_softirqs (kernel/softirq.c:561)
 __irq_exit_rcu (kernel/softirq.c:596 kernel/softirq.c:435 kernel/softirq.c:662)
 irq_exit_rcu (kernel/softirq.c:680)
 common_interrupt (arch/x86/kernel/irq.c:280 (discriminator 14))
  </IRQ>
 <TASK>
 asm_common_interrupt (./arch/x86/include/asm/idtentry.h:693)
RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:744)
Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d c3 2b 15 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffa00000000ffee8 EFLAGS: 00000202
RAX: 000000000000640b RBX: ff1100010091c200 RCX: 0000000000061aa4
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff812f30c5
RBP: 000000000000000a R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 ? do_idle (kernel/sched/idle.c:186 kernel/sched/idle.c:325)
 default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118)
 do_idle (kernel/sched/idle.c:186 kernel/sched/idle.c:325)
 cpu_startup_entry (kernel/sched/idle.c:422 (discriminator 1))
 start_secondary (arch/x86/kernel/smpboot.c:315)
 common_startup_64 (arch/x86/kernel/head_64.S:421)
 </TASK>
Modules linked in: cifs_arc4 nls_ucs2_utils cifs_md4 [last unloaded: cifs]
CR2: 00000000000000c4

Fixes: ed07536ed673 ("[PATCH] lockdep: annotate nfs/nfsd in-kernel sockets")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250407163313.22682-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
wifi: mac80211: add strict mode disabling workarounds 2025-04-20T08:22:31+00:00 Johannes Berg johannes.berg@intel.com 2025-02-05T09:39:16+00:00 5ccfc6939e130eefe857de816b948757d68cd868 [ Upstream commit 3ad4fce66e4f9d82abfc366707757e29cc14a9d2 ] Add a strict mode where we disable certain workarounds and have additional checks such as, for now, that VHT capabilities from association response match those from beacon/probe response. We can extend the checks in the future. Make it an opt-in setting by the driver so it can be set there in some driver-specific way, for example. Also allow setting this one hw flag through the hwflags debugfs, by writing a new strict=0 or strict=1 value. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Ilan Peer <ilan.peer@intel.com> Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com> Link: https://patch.msgid.link/20250205110958.5cecb0469479.I4a69617dc60ba0d6308416ffbc3102cfd08ba068@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3ad4fce66e4f9d82abfc366707757e29cc14a9d2 ]

Add a strict mode where we disable certain workarounds and have
additional checks such as, for now, that VHT capabilities from
association response match those from beacon/probe response. We
can extend the checks in the future.

Make it an opt-in setting by the driver so it can be set there
in some driver-specific way, for example. Also allow setting
this one hw flag through the hwflags debugfs, by writing a new
strict=0 or strict=1 value.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250205110958.5cecb0469479.I4a69617dc60ba0d6308416ffbc3102cfd08ba068@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
xsk: Add launch time hardware offload support to XDP Tx metadata 2025-04-10T12:44:39+00:00 Song Yoong Siang yoong.siang.song@intel.com 2025-02-16T09:34:26+00:00 d9d736c416c9a85f84e15435ba82a177262e745b [ Upstream commit ca4419f15abd19ba8be1e109661b60f9f5b6c9f0 ] Extend the XDP Tx metadata framework so that user can requests launch time hardware offload, where the Ethernet device will schedule the packet for transmission at a pre-determined time called launch time. The value of launch time is communicated from user space to Ethernet driver via launch_time field of struct xsk_tx_metadata. Suggested-by: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20250216093430.957880-2-yoong.siang.song@intel.com Stable-dep-of: d931cf9b38da ("igc: Fix TX drops in XDP ZC") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ca4419f15abd19ba8be1e109661b60f9f5b6c9f0 ]

Extend the XDP Tx metadata framework so that user can requests launch time
hardware offload, where the Ethernet device will schedule the packet for
transmission at a pre-determined time called launch time. The value of
launch time is communicated from user space to Ethernet driver via
launch_time field of struct xsk_tx_metadata.

Suggested-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250216093430.957880-2-yoong.siang.song@intel.com
Stable-dep-of: d931cf9b38da ("igc: Fix TX drops in XDP ZC")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Bluetooth: HCI: Add definition of hci_rp_remote_name_req_cancel 2025-04-10T12:44:14+00:00 Wentao Guan guanwentao@uniontech.com 2025-03-17T18:50:34+00:00 44073ccc09e6b64951ce2347234bd89a0059f0f3 [ Upstream commit e8c00f5433d020a2230226abe7e43f43dc686920 ] Return Parameters is not only status, also bdaddr: BLUETOOTH CORE SPECIFICATION Version 5.4 | Vol 4, Part E page 1870: BLUETOOTH CORE SPECIFICATION Version 5.0 | Vol 2, Part E page 802: Return parameters: Status: Size: 1 octet BD_ADDR: Size: 6 octets Note that it also fixes the warning: "Bluetooth: hci0: unexpected cc 0x041a length: 7 > 1" Fixes: c8992cffbe741 ("Bluetooth: hci_event: Use of a function table to handle Command Complete") Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e8c00f5433d020a2230226abe7e43f43dc686920 ]

Return Parameters is not only status, also bdaddr:

BLUETOOTH CORE SPECIFICATION Version 5.4 | Vol 4, Part E
page 1870:
BLUETOOTH CORE SPECIFICATION Version 5.0 | Vol 2, Part E
page 802:

Return parameters:
  Status:
  Size: 1 octet
  BD_ADDR:
  Size: 6 octets

Note that it also fixes the warning:
"Bluetooth: hci0: unexpected cc 0x041a length: 7 > 1"

Fixes: c8992cffbe741 ("Bluetooth: hci_event: Use of a function table to handle Command Complete")
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Bluetooth: hci_core: Enable buffer flow control for SCO/eSCO 2025-04-10T12:44:14+00:00 Luiz Augusto von Dentz luiz.von.dentz@intel.com 2025-03-12T15:14:20+00:00 2c778debf67ed7572fc6eca208015501ea6f6678 [ Upstream commit 13218453521d75916dfed55efb8e809bfc03cb4b ] This enables buffer flow control for SCO/eSCO (see: Bluetooth Core 6.0 spec: 6.22. Synchronous Flow Control Enable), recently this has caused the following problem and is actually a nice addition for the likes of Socket TX complete: < HCI Command: Read Buffer Size (0x04|0x0005) plen 0 > HCI Event: Command Complete (0x0e) plen 11 Read Buffer Size (0x04|0x0005) ncmd 1 Status: Success (0x00) ACL MTU: 1021 ACL max packet: 5 SCO MTU: 240 SCO max packet: 8 ... < SCO Data TX: Handle 257 flags 0x00 dlen 120 < SCO Data TX: Handle 257 flags 0x00 dlen 120 < SCO Data TX: Handle 257 flags 0x00 dlen 120 < SCO Data TX: Handle 257 flags 0x00 dlen 120 < SCO Data TX: Handle 257 flags 0x00 dlen 120 < SCO Data TX: Handle 257 flags 0x00 dlen 120 < SCO Data TX: Handle 257 flags 0x00 dlen 120 < SCO Data TX: Handle 257 flags 0x00 dlen 120 < SCO Data TX: Handle 257 flags 0x00 dlen 120 > HCI Event: Hardware Error (0x10) plen 1 Code: 0x0a To fix the code will now attempt to enable buffer flow control when HCI_QUIRK_SYNC_FLOWCTL_SUPPORTED is set by the driver: < HCI Command: Write Sync Fl.. (0x03|0x002f) plen 1 Flow control: Enabled (0x01) > HCI Event: Command Complete (0x0e) plen 4 Write Sync Flow Control Enable (0x03|0x002f) ncmd 1 Status: Success (0x00) On success then HCI_SCO_FLOWCTL would be set which indicates sco_cnt shall be used for flow contro. Fixes: 7fedd3bb6b77 ("Bluetooth: Prioritize SCO traffic") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Tested-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 13218453521d75916dfed55efb8e809bfc03cb4b ]

This enables buffer flow control for SCO/eSCO
(see: Bluetooth Core 6.0 spec: 6.22. Synchronous Flow Control Enable),
recently this has caused the following problem and is actually a nice
addition for the likes of Socket TX complete:

< HCI Command: Read Buffer Size (0x04|0x0005) plen 0
> HCI Event: Command Complete (0x0e) plen 11
      Read Buffer Size (0x04|0x0005) ncmd 1
        Status: Success (0x00)
        ACL MTU: 1021 ACL max packet: 5
        SCO MTU: 240  SCO max packet: 8
...
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
< SCO Data TX: Handle 257 flags 0x00 dlen 120
> HCI Event: Hardware Error (0x10) plen 1
        Code: 0x0a

To fix the code will now attempt to enable buffer flow control when
HCI_QUIRK_SYNC_FLOWCTL_SUPPORTED is set by the driver:

< HCI Command: Write Sync Fl.. (0x03|0x002f) plen 1
        Flow control: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4
      Write Sync Flow Control Enable (0x03|0x002f) ncmd 1
        Status: Success (0x00)

On success then HCI_SCO_FLOWCTL would be set which indicates sco_cnt
shall be used for flow contro.

Fixes: 7fedd3bb6b77 ("Bluetooth: Prioritize SCO traffic")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Bluetooth: Add quirk for broken READ_PAGE_SCAN_TYPE 2025-04-10T12:44:13+00:00 Pedro Nishiyama nishiyama.pedro@gmail.com 2025-03-01T06:22:59+00:00 05dc261b600266d202ea9cb6d1e230c2990d7493 [ Upstream commit 127881334eaad639e0a19a399ee8c91d6c9dc982 ] Some fake controllers cannot be initialized because they return a smaller report than expected for READ_PAGE_SCAN_TYPE. Signed-off-by: Pedro Nishiyama <nishiyama.pedro@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Stable-dep-of: 1f04b0e5e3b9 ("Bluetooth: btusb: Fix regression in the initialization of fake Bluetooth controllers") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 127881334eaad639e0a19a399ee8c91d6c9dc982 ]

Some fake controllers cannot be initialized because they return a smaller
report than expected for READ_PAGE_SCAN_TYPE.

Signed-off-by: Pedro Nishiyama <nishiyama.pedro@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Stable-dep-of: 1f04b0e5e3b9 ("Bluetooth: btusb: Fix regression in the initialization of fake Bluetooth controllers")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Bluetooth: Add quirk for broken READ_VOICE_SETTING 2025-04-10T12:44:13+00:00 Pedro Nishiyama nishiyama.pedro@gmail.com 2025-03-01T06:22:58+00:00 a256de0d34e5937da8e9e0b23a8fa17ec32afa7d [ Upstream commit ff26b2dd6568392f60fa67a4e58279938025c3af ] Some fake controllers cannot be initialized because they return a smaller report than expected for READ_VOICE_SETTING. Signed-off-by: Pedro Nishiyama <nishiyama.pedro@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Stable-dep-of: 1f04b0e5e3b9 ("Bluetooth: btusb: Fix regression in the initialization of fake Bluetooth controllers") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ff26b2dd6568392f60fa67a4e58279938025c3af ]

Some fake controllers cannot be initialized because they return a smaller
report than expected for READ_VOICE_SETTING.

Signed-off-by: Pedro Nishiyama <nishiyama.pedro@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Stable-dep-of: 1f04b0e5e3b9 ("Bluetooth: btusb: Fix regression in the initialization of fake Bluetooth controllers")
Signed-off-by: Sasha Levin <sashal@kernel.org>
bonding: check xdp prog when set bond mode 2025-04-10T12:44:13+00:00 Wang Liang wangliang74@huawei.com 2025-03-21T04:48:52+00:00 0dd4fac43bdea23cfe4bb2a3eabb76d752ac32fb [ Upstream commit 094ee6017ea09c11d6af187935a949df32803ce0 ] Following operations can trigger a warning[1]: ip netns add ns1 ip netns exec ns1 ip link add bond0 type bond mode balance-rr ip netns exec ns1 ip link set dev bond0 xdp obj af_xdp_kern.o sec xdp ip netns exec ns1 ip link set bond0 type bond mode broadcast ip netns del ns1 When delete the namespace, dev_xdp_uninstall() is called to remove xdp program on bond dev, and bond_xdp_set() will check the bond mode. If bond mode is changed after attaching xdp program, the warning may occur. Some bond modes (broadcast, etc.) do not support native xdp. Set bond mode with xdp program attached is not good. Add check for xdp program when set bond mode. [1] ------------[ cut here ]------------ WARNING: CPU: 0 PID: 11 at net/core/dev.c:9912 unregister_netdevice_many_notify+0x8d9/0x930 Modules linked in: CPU: 0 UID: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.14.0-rc4 #107 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Workqueue: netns cleanup_net RIP: 0010:unregister_netdevice_many_notify+0x8d9/0x930 Code: 00 00 48 c7 c6 6f e3 a2 82 48 c7 c7 d0 b3 96 82 e8 9c 10 3e ... RSP: 0018:ffffc90000063d80 EFLAGS: 00000282 RAX: 00000000ffffffa1 RBX: ffff888004959000 RCX: 00000000ffffdfff RDX: 0000000000000000 RSI: 00000000ffffffea RDI: ffffc90000063b48 RBP: ffffc90000063e28 R08: ffffffff82d39b28 R09: 0000000000009ffb R10: 0000000000000175 R11: ffffffff82d09b40 R12: ffff8880049598e8 R13: 0000000000000001 R14: dead000000000100 R15: ffffc90000045000 FS: 0000000000000000(0000) GS:ffff888007a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000d406b60 CR3: 000000000483e000 CR4: 00000000000006f0 Call Trace: <TASK> ? __warn+0x83/0x130 ? unregister_netdevice_many_notify+0x8d9/0x930 ? report_bug+0x18e/0x1a0 ? handle_bug+0x54/0x90 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? unregister_netdevice_many_notify+0x8d9/0x930 ? bond_net_exit_batch_rtnl+0x5c/0x90 cleanup_net+0x237/0x3d0 process_one_work+0x163/0x390 worker_thread+0x293/0x3b0 ? __pfx_worker_thread+0x10/0x10 kthread+0xec/0x1e0 ? __pfx_kthread+0x10/0x10 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2f/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> ---[ end trace 0000000000000000 ]--- Fixes: 9e2ee5c7e7c3 ("net, bonding: Add XDP support to the bonding driver") Signed-off-by: Wang Liang <wangliang74@huawei.com> Acked-by: Jussi Maki <joamaki@gmail.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20250321044852.1086551-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 094ee6017ea09c11d6af187935a949df32803ce0 ]

Following operations can trigger a warning[1]:

    ip netns add ns1
    ip netns exec ns1 ip link add bond0 type bond mode balance-rr
    ip netns exec ns1 ip link set dev bond0 xdp obj af_xdp_kern.o sec xdp
    ip netns exec ns1 ip link set bond0 type bond mode broadcast
    ip netns del ns1

When delete the namespace, dev_xdp_uninstall() is called to remove xdp
program on bond dev, and bond_xdp_set() will check the bond mode. If bond
mode is changed after attaching xdp program, the warning may occur.

Some bond modes (broadcast, etc.) do not support native xdp. Set bond mode
with xdp program attached is not good. Add check for xdp program when set
bond mode.

    [1]
    ------------[ cut here ]------------
    WARNING: CPU: 0 PID: 11 at net/core/dev.c:9912 unregister_netdevice_many_notify+0x8d9/0x930
    Modules linked in:
    CPU: 0 UID: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.14.0-rc4 #107
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
    Workqueue: netns cleanup_net
    RIP: 0010:unregister_netdevice_many_notify+0x8d9/0x930
    Code: 00 00 48 c7 c6 6f e3 a2 82 48 c7 c7 d0 b3 96 82 e8 9c 10 3e ...
    RSP: 0018:ffffc90000063d80 EFLAGS: 00000282
    RAX: 00000000ffffffa1 RBX: ffff888004959000 RCX: 00000000ffffdfff
    RDX: 0000000000000000 RSI: 00000000ffffffea RDI: ffffc90000063b48
    RBP: ffffc90000063e28 R08: ffffffff82d39b28 R09: 0000000000009ffb
    R10: 0000000000000175 R11: ffffffff82d09b40 R12: ffff8880049598e8
    R13: 0000000000000001 R14: dead000000000100 R15: ffffc90000045000
    FS:  0000000000000000(0000) GS:ffff888007a00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 000000000d406b60 CR3: 000000000483e000 CR4: 00000000000006f0
    Call Trace:
     <TASK>
     ? __warn+0x83/0x130
     ? unregister_netdevice_many_notify+0x8d9/0x930
     ? report_bug+0x18e/0x1a0
     ? handle_bug+0x54/0x90
     ? exc_invalid_op+0x18/0x70
     ? asm_exc_invalid_op+0x1a/0x20
     ? unregister_netdevice_many_notify+0x8d9/0x930
     ? bond_net_exit_batch_rtnl+0x5c/0x90
     cleanup_net+0x237/0x3d0
     process_one_work+0x163/0x390
     worker_thread+0x293/0x3b0
     ? __pfx_worker_thread+0x10/0x10
     kthread+0xec/0x1e0
     ? __pfx_kthread+0x10/0x10
     ? __pfx_kthread+0x10/0x10
     ret_from_fork+0x2f/0x50
     ? __pfx_kthread+0x10/0x10
     ret_from_fork_asm+0x1a/0x30
     </TASK>
    ---[ end trace 0000000000000000 ]---

Fixes: 9e2ee5c7e7c3 ("net, bonding: Add XDP support to the bonding driver")
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Acked-by: Jussi Maki <joamaki@gmail.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250321044852.1086551-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ax25: Remove broken autobind 2025-04-10T12:44:12+00:00 Murad Masimov m.masimov@mt-integration.ru 2025-03-17T10:53:52+00:00 61203fdd3e35519db9a98b6ff8983c620ffc4696 [ Upstream commit 2f6efbabceb6b2914ee9bafb86d9a51feae9cce8 ] Binding AX25 socket by using the autobind feature leads to memory leaks in ax25_connect() and also refcount leaks in ax25_release(). Memory leak was detected with kmemleak: ================================================================ unreferenced object 0xffff8880253cd680 (size 96): backtrace: __kmalloc_node_track_caller_noprof (./include/linux/kmemleak.h:43) kmemdup_noprof (mm/util.c:136) ax25_rt_autobind (net/ax25/ax25_route.c:428) ax25_connect (net/ax25/af_ax25.c:1282) __sys_connect_file (net/socket.c:2045) __sys_connect (net/socket.c:2064) __x64_sys_connect (net/socket.c:2067) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) ================================================================ When socket is bound, refcounts must be incremented the way it is done in ax25_bind() and ax25_setsockopt() (SO_BINDTODEVICE). In case of autobind, the refcounts are not incremented. This bug leads to the following issue reported by Syzkaller: ================================================================ ax25_connect(): syz-executor318 uses autobind, please contact jreuter@yaina.de ------------[ cut here ]------------ refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 0 PID: 5317 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31 Modules linked in: CPU: 0 UID: 0 PID: 5317 Comm: syz-executor318 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #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+0xfa/0x1d0 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+0x6af/0x7e0 lib/ref_tracker.c:236 netdev_tracker_free include/linux/netdevice.h:4302 [inline] netdev_put include/linux/netdevice.h:4319 [inline] ax25_release+0x368/0x960 net/ax25/af_ax25.c:1080 __sock_release net/socket.c:647 [inline] sock_close+0xbc/0x240 net/socket.c:1398 __fput+0x3e9/0x9f0 fs/file_table.c:464 __do_sys_close fs/open.c:1580 [inline] __se_sys_close fs/open.c:1565 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1565 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f ... </TASK> ================================================================ Considering the issues above and the comments left in the code that say: "check if we can remove this feature. It is broken."; "autobinding in this may or may not work"; - it is better to completely remove this feature than to fix it because it is broken and leads to various kinds of memory bugs. Now calling connect() without first binding socket will result in an error (-EINVAL). Userspace software that relies on the autobind feature might get broken. However, this feature does not seem widely used with this specific driver as it was not reliable at any point of time, and it is already broken anyway. E.g. ax25-tools and ax25-apps packages for popular distributions do not use the autobind feature for AF_AX25. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+33841dc6aa3e1d86b78a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=33841dc6aa3e1d86b78a Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2f6efbabceb6b2914ee9bafb86d9a51feae9cce8 ]

Binding AX25 socket by using the autobind feature leads to memory leaks
in ax25_connect() and also refcount leaks in ax25_release(). Memory
leak was detected with kmemleak:

================================================================
unreferenced object 0xffff8880253cd680 (size 96):
backtrace:
__kmalloc_node_track_caller_noprof (./include/linux/kmemleak.h:43)
kmemdup_noprof (mm/util.c:136)
ax25_rt_autobind (net/ax25/ax25_route.c:428)
ax25_connect (net/ax25/af_ax25.c:1282)
__sys_connect_file (net/socket.c:2045)
__sys_connect (net/socket.c:2064)
__x64_sys_connect (net/socket.c:2067)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
================================================================

When socket is bound, refcounts must be incremented the way it is done
in ax25_bind() and ax25_setsockopt() (SO_BINDTODEVICE). In case of
autobind, the refcounts are not incremented.

This bug leads to the following issue reported by Syzkaller:

================================================================
ax25_connect(): syz-executor318 uses autobind, please contact jreuter@yaina.de
------------[ cut here ]------------
refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 5317 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:31
Modules linked in:
CPU: 0 UID: 0 PID: 5317 Comm: syz-executor318 Not tainted 6.14.0-rc4-syzkaller-00278-gece144f151ac #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+0xfa/0x1d0 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+0x6af/0x7e0 lib/ref_tracker.c:236
 netdev_tracker_free include/linux/netdevice.h:4302 [inline]
 netdev_put include/linux/netdevice.h:4319 [inline]
 ax25_release+0x368/0x960 net/ax25/af_ax25.c:1080
 __sock_release net/socket.c:647 [inline]
 sock_close+0xbc/0x240 net/socket.c:1398
 __fput+0x3e9/0x9f0 fs/file_table.c:464
 __do_sys_close fs/open.c:1580 [inline]
 __se_sys_close fs/open.c:1565 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1565
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
 ...
 </TASK>
================================================================

Considering the issues above and the comments left in the code that say:
"check if we can remove this feature. It is broken."; "autobinding in this
may or may not work"; - it is better to completely remove this feature than
to fix it because it is broken and leads to various kinds of memory bugs.

Now calling connect() without first binding socket will result in an
error (-EINVAL). Userspace software that relies on the autobind feature
might get broken. However, this feature does not seem widely used with
this specific driver as it was not reliable at any point of time, and it
is already broken anyway. E.g. ax25-tools and ax25-apps packages for
popular distributions do not use the autobind feature for AF_AX25.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+33841dc6aa3e1d86b78a@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=33841dc6aa3e1d86b78a
Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>