[v6.1] possible deadlock in hsr_dev_xmit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 88690811da69 Linux 6.1.92
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=171718ca980000
kernel config: https://syzkaller.appspot.com/x/.config?x=f084fbeeff2de042
dashboard link: https://syzkaller.appspot.com/bug?extid=20e19083aa5ab88790b4
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9040ec940045/disk-88690811.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dc70128611fd/vmlinux-88690811.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f05abc0b618b/Image-88690811.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+20e190...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
6.1.92-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.2/10644 is trying to acquire lock:
ffff0000ed7c8d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff0000ed7c8d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0xf8/0x2d8 net/hsr/hsr_device.c:219

but task is already holding lock:
ffff0000f14d0d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff0000f14d0d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x1fc/0x8a4 net/hsr/hsr_device.c:300

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&hsr->seqnr_lock);
lock(&hsr->seqnr_lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

8 locks held by syz-executor.2/10644:
#0: ffff0000e795b590 (&u->iolock){+.+.}-{3:3}, at: __unix_dgram_recvmsg+0x1ec/0xe2c net/unix/af_unix.c:2443
#1: ffff800008007c80 ((&hsr->announce_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
#1: ffff800008007c80 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd0/0xa1c kernel/time/timer.c:1494
#2: ffff800015a24ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349
#3: ffff0000f14d0d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#3: ffff0000f14d0d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x1fc/0x8a4 net/hsr/hsr_device.c:300
#4: ffff800015a24ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349
#5: ffff800015a24d00 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:349
#6: ffff800015a24ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349
#7: ffff800015a24d00 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:349

stack backtrace:
CPU: 0 PID: 10644 Comm: syz-executor.2 Not tainted 6.1.92-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x5c lib/dump_stack.c:113
__lock_acquire+0x6310/0x7680 kernel/locking/lockdep.c:5049
lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x54/0x6c kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
hsr_dev_xmit+0xf8/0x2d8 net/hsr/hsr_device.c:219
__netdev_start_xmit include/linux/netdevice.h:4853 [inline]
netdev_start_xmit include/linux/netdevice.h:4867 [inline]
xmit_one net/core/dev.c:3627 [inline]
dev_hard_start_xmit+0x25c/0x9a4 net/core/dev.c:3643
__dev_queue_xmit+0x186c/0x38d8 net/core/dev.c:4293
dev_queue_xmit include/linux/netdevice.h:3021 [inline]
br_dev_queue_push_xmit+0x584/0x730 net/bridge/br_forward.c:53
NF_HOOK+0x35c/0x408 include/linux/netfilter.h:302
br_forward_finish+0xd0/0x118 net/bridge/br_forward.c:66
NF_HOOK+0x35c/0x408 include/linux/netfilter.h:302
__br_forward+0x2f0/0x458 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver+0xc8/0x178 net/bridge/br_forward.c:189
br_flood+0x28c/0x3f8 net/bridge/br_forward.c:231
br_dev_xmit+0xd88/0x137c
__netdev_start_xmit include/linux/netdevice.h:4853 [inline]
netdev_start_xmit include/linux/netdevice.h:4867 [inline]
xmit_one net/core/dev.c:3627 [inline]
dev_hard_start_xmit+0x25c/0x9a4 net/core/dev.c:3643
__dev_queue_xmit+0x186c/0x38d8 net/core/dev.c:4293
dev_queue_xmit include/linux/netdevice.h:3021 [inline]
hsr_xmit net/hsr/hsr_forward.c:380 [inline]
hsr_forward_do net/hsr/hsr_forward.c:471 [inline]
hsr_forward_skb+0x1048/0x1c5c net/hsr/hsr_forward.c:619
send_hsr_supervision_frame+0x414/0x8a4 net/hsr/hsr_device.c:323
hsr_announce+0x17c/0x31c net/hsr/hsr_device.c:379
call_timer_fn+0x1c0/0xa1c kernel/time/timer.c:1504
expire_timers kernel/time/timer.c:1549 [inline]
__run_timers+0x554/0x718 kernel/time/timer.c:1820
run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833
__do_softirq+0x314/0xe38 kernel/softirq.c:571
____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893
do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0x264/0x4d4 kernel/softirq.c:650
irq_exit_rcu+0x14/0x84 kernel/softirq.c:662
__el1_irq arch/arm64/kernel/entry-common.c:472 [inline]
el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581
arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x58/0xac kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
__skb_try_recv_datagram+0x198/0x584 net/core/datagram.c:265
__unix_dgram_recvmsg+0x2f8/0xe2c net/unix/af_unix.c:2446
unix_dgram_recvmsg+0xd0/0xe8 net/unix/af_unix.c:2543
____sys_recvmsg+0x234/0x69c
___sys_recvmsg net/socket.c:2775 [inline]
do_recvmmsg+0x41c/0xb60 net/socket.c:2869
__sys_recvmmsg net/socket.c:2948 [inline]
__do_sys_recvmmsg net/socket.c:2971 [inline]
__se_sys_recvmmsg net/socket.c:2964 [inline]
__arm64_sys_recvmmsg+0x180/0x23c net/socket.c:2964
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585


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