============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.1.655/8042 is trying to acquire lock:
ffff888059ca8fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
ffff888059ca8fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
but task is already holding lock:
ffff88807ada8fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
ffff88807ada8fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330
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
9 locks held by syz.1.655/8042:
#0: ffff88805582e140 ((wq_completion)nfc3_nci_rx_wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0xb5/0x180 kernel/workqueue.c:4003
#1: ffffc90000a08cc0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5e0 kernel/time/timer.c:1745
#2: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#2: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x89/0x370 net/hsr/hsr_device.c:419
#3: ffff88807ada8fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
#3: ffff88807ada8fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330
#4: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#4: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xbb/0x2a80 net/hsr/hsr_forward.c:738
#5: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#5: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#5: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791
#6: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#6: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#6: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x193/0x1990 net/bridge/br_device.c:52
#7: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#7: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#7: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791
#8: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#8: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#8: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229
stack backtrace:
CPU: 1 UID: 0 PID: 8042 Comm: syz.1.655 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
check_deadlock kernel/locking/lockdep.c:3093 [inline]
validate_chain kernel/locking/lockdep.c:3895 [inline]
__lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:182
spin_lock_bh include/linux/spinlock.h:348 [inline]
hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
__netdev_start_xmit include/linux/netdevice.h:5343 [inline]
netdev_start_xmit include/linux/netdevice.h:5352 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
__dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870
dev_queue_xmit include/linux/netdevice.h:3401 [inline]
br_dev_queue_push_xmit+0x370/0x4b0 net/bridge/br_forward.c:53
NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:318
br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:318
__br_forward+0x397/0x540 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver net/bridge/br_forward.c:191 [inline]
br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238
br_dev_xmit+0x12bd/0x1990 net/bridge/br_device.c:108
__netdev_start_xmit include/linux/netdevice.h:5343 [inline]
netdev_start_xmit include/linux/netdevice.h:5352 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
__dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870
dev_queue_xmit include/linux/netdevice.h:3401 [inline]
hsr_xmit net/hsr/hsr_forward.c:440 [inline]
hsr_forward_do net/hsr/hsr_forward.c:581 [inline]
hsr_forward_skb+0x167e/0x2a80 net/hsr/hsr_forward.c:743
send_hsr_supervision_frame+0x731/0xcb0 net/hsr/hsr_device.c:364
hsr_announce+0x1db/0x370 net/hsr/hsr_device.c:421
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 b1 9d 11 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 8b 38 9c 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 98 f2 93
RSP: 0018:ffffc9001b5f79e8 EFLAGS: 00000286
RAX: 998a1e4434fe3200 RBX: 0000000000000000 RCX: 0000000000000046
RDX: ffffffff940184d8 RSI: ffffffff8e22a119 RDI: ffffffff8c27f000
RBP: ffffffff818d6725 R08: 000000000000ff00 R09: 0000000087cf3032
R10: 0000000091ae7a12 R11: 000000003fb0f1c0 R12: 0000000000000000
R13: ffff88805582e140 R14: 0000000000000001 R15: 0000000000000246
touch_wq_lockdep_map+0xcb/0x180 kernel/workqueue.c:4003
__flush_workqueue+0x14b/0x14f0 kernel/workqueue.c:4045
drain_workqueue+0xd3/0x390 kernel/workqueue.c:4209
destroy_workqueue+0xbb/0xc60 kernel/workqueue.c:5979
nci_unregister_device+0xae/0x260 net/nfc/nci/core.c:1333
virtual_ncidev_close+0x56/0x90 drivers/nfc/virtual_ncidev.c:168
__fput+0x44f/0xa60 fs/file_table.c:510
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa951b9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe8bea1b48 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fa951e17da0 RCX: 00007fa951b9cdd9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fa951e17da0 R08: 00007fa951e16128 R09: 0000000000000000
R10: 00000000003ffbdc R11: 0000000000000246 R12: 00000000000232f9
R13: 00007fa951e1609c R14: 00000000000230e0 R15: 00007ffe8bea1c50
----------------
Code disassembly (best guess), 2 bytes skipped:
0: ff ljmp (bad)
1: e8 b1 9d 11 0a call 0xa119db7
6: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp)
d: 00
e: 0f 84 3a ff ff ff je 0xffffff4e
14: 65 48 8b 05 8b 38 9c mov %gs:0x119c388b(%rip),%rax # 0x119c38a7
1b: 11
1c: 48 3b 44 24 58 cmp 0x58(%rsp),%rax
21: 75 33 jne 0x56
23: fb sti
24: 48 83 c4 60 add $0x60,%rsp
* 28: 5b pop %rbx <-- trapping instruction
29: 41 5c pop %r12
2b: 41 5d pop %r13
2d: 41 5e pop %r14
2f: 41 5f pop %r15
31: 5d pop %rbp
32: c3 ret
33: cc int3
34: cc int3
35: cc int3
36: cc int3
37: cc int3
38: 48 rex.W
39: 8d .byte 0x8d
3a: 3d .byte 0x3d
3b: 98 cwtl
3c: f2 93 repnz xchg %eax,%ebx