============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/0:8/5920 is trying to acquire lock:
ffff888085194fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:347 [inline]
ffff888085194fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
but task is already holding lock:
ffff8880af9ccfb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:347 [inline]
ffff8880af9ccfb0 (&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
10 locks held by kworker/0:8/5920:
#0: ffff88813fe0f148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88813fe0f148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc9000472fc40 ((work_completion)(&p->wq)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc9000472fc40 ((work_completion)(&p->wq)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffffc90000007ce0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x640 kernel/time/timer.c:1745
#3: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#3: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#3: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x89/0x370 net/hsr/hsr_device.c:419
#4: ffff8880af9ccfb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:347 [inline]
#4: ffff8880af9ccfb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330
#5: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#5: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#5: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb3/0x2860 net/hsr/hsr_forward.c:738
#6: ffffffff8e75e680 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#6: ffffffff8e75e680 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline]
#6: ffffffff8e75e680 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x28b/0x3870 net/core/dev.c:4772
#7: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#7: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#7: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x193/0x1980 net/bridge/br_device.c:52
#8: ffffffff8e75e680 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#8: ffffffff8e75e680 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline]
#8: ffffffff8e75e680 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x28b/0x3870 net/core/dev.c:4772
#9: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#9: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#9: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229
stack backtrace:
CPU: 0 UID: 0 PID: 5920 Comm: kworker/0:8 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events delayed_vfree_work
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+0xf0/0x2e0 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:178
spin_lock_bh include/linux/spinlock.h:347 [inline]
hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
__netdev_start_xmit include/linux/netdevice.h:5334 [inline]
netdev_start_xmit include/linux/netdevice.h:5343 [inline]
xmit_one net/core/dev.c:3881 [inline]
dev_hard_start_xmit+0x2d8/0x870 net/core/dev.c:3897
__dev_queue_xmit+0x1557/0x3870 net/core/dev.c:4852
dev_queue_xmit include/linux/netdevice.h:3394 [inline]
br_dev_queue_push_xmit+0x370/0x4a0 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/0x1980 net/bridge/br_device.c:108
__netdev_start_xmit include/linux/netdevice.h:5334 [inline]
netdev_start_xmit include/linux/netdevice.h:5343 [inline]
xmit_one net/core/dev.c:3881 [inline]
dev_hard_start_xmit+0x2d8/0x870 net/core/dev.c:3897
__dev_queue_xmit+0x1557/0x3870 net/core/dev.c:4852
dev_queue_xmit include/linux/netdevice.h:3394 [inline]
hsr_xmit net/hsr/hsr_forward.c:440 [inline]
hsr_forward_do net/hsr/hsr_forward.c:581 [inline]
hsr_forward_skb+0x157b/0x2860 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+0x192/0x640 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2373 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
run_timer_base kernel/time/timer.c:2394 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:194
Code: f7 e8 1d 61 ee f5 f7 c3 00 02 00 00 74 05 e8 10 c7 19 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e4 1d e0 f5 65 8b 05 0d e0 68 07 85 c0 74 18 5b 41 5e c3 cc cc
RSP: 0018:ffffc9000472f970 EFLAGS: 00000206
RAX: 0000000000000002 RBX: 0000000000000286 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8df2736e RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff901187b7 R09: 1ffffffff20230f6
R10: dffffc0000000000 R11: fffffbfff20230f7 R12: ffffc90012400000
R13: ffffc90011a00000 R14: ffffffff9a4e3678 R15: 000000000000081a
__debug_check_no_obj_freed lib/debugobjects.c:1125 [inline]
debug_check_no_obj_freed+0x52e/0x550 lib/debugobjects.c:1146
remove_vm_area+0x1d3/0x300 mm/vmalloc.c:3336
vfree+0x63/0x400 mm/vmalloc.c:3459
delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3398
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: f7 e8 imul %eax
2: 1d 61 ee f5 f7 sbb $0xf7f5ee61,%eax
7: c3 ret
8: 00 02 add %al,(%rdx)
a: 00 00 add %al,(%rax)
c: 74 05 je 0x13
e: e8 10 c7 19 f6 call 0xf619c723
13: 9c pushf
14: 58 pop %rax
15: a9 00 02 00 00 test $0x200,%eax
1a: 75 27 jne 0x43
1c: f7 c3 00 02 00 00 test $0x200,%ebx
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 e4 1d e0 f5 call 0xf5e01e13 <-- trapping instruction
2f: 65 8b 05 0d e0 68 07 mov %gs:0x768e00d(%rip),%eax # 0x768e043
36: 85 c0 test %eax,%eax
38: 74 18 je 0x52
3a: 5b pop %rbx
3b: 41 5e pop %r14
3d: c3 ret
3e: cc int3
3f: cc int3