============================================
WARNING: possible recursive locking detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
--------------------------------------------
kworker/u8:5/979 is trying to acquire lock:
ffff8880230b0da0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff8880230b0da0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0x13e/0x1d0 net/hsr/hsr_device.c:229
but task is already holding lock:
ffff88801130eda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff88801130eda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x276/0xad0 net/hsr/hsr_device.c:310
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 kworker/u8:5/979:
#0: ffff88802aae9148 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
#0: ffff88802aae9148 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
#1: ffffc9000410fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
#1: ffffc9000410fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
#2: ffffc90000a08c00 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hsr_announce+0xa3/0x370 net/hsr/hsr_device.c:387
#4: ffff88801130eda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#4: ffff88801130eda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x276/0xad0 net/hsr/hsr_device.c:310
#5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hsr_forward_skb+0xae/0x2400 net/hsr/hsr_forward.c:614
#6: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#6: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
#6: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260
#7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x1b9/0x1a10 net/bridge/br_device.c:44
#8: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#8: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
#8: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260
stack backtrace:
CPU: 1 PID: 979 Comm: kworker/u8:5 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: bat_events batadv_nc_worker
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
__lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
hsr_dev_xmit+0x13e/0x1d0 net/hsr/hsr_device.c:229
__netdev_start_xmit include/linux/netdevice.h:4903 [inline]
netdev_start_xmit include/linux/netdevice.h:4917 [inline]
xmit_one net/core/dev.c:3531 [inline]
dev_hard_start_xmit+0x26c/0x790 net/core/dev.c:3547
__dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335
dev_queue_xmit include/linux/netdevice.h:3091 [inline]
br_dev_queue_push_xmit+0x701/0x8d0 net/bridge/br_forward.c:53
NF_HOOK+0x3a9/0x460 include/linux/netfilter.h:314
br_forward_finish+0xe5/0x140 net/bridge/br_forward.c:66
NF_HOOK+0x3a9/0x460 include/linux/netfilter.h:314
__br_forward+0x489/0x660 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:190
br_flood+0x2e4/0x660 net/bridge/br_forward.c:236
br_dev_xmit+0x118c/0x1a10
__netdev_start_xmit include/linux/netdevice.h:4903 [inline]
netdev_start_xmit include/linux/netdevice.h:4917 [inline]
xmit_one net/core/dev.c:3531 [inline]
dev_hard_start_xmit+0x26c/0x790 net/core/dev.c:3547
__dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335
dev_queue_xmit include/linux/netdevice.h:3091 [inline]
hsr_xmit net/hsr/hsr_forward.c:380 [inline]
hsr_forward_do net/hsr/hsr_forward.c:471 [inline]
hsr_forward_skb+0x183f/0x2400 net/hsr/hsr_forward.c:619
send_hsr_supervision_frame+0x548/0xad0 net/hsr/hsr_device.c:333
hsr_announce+0x1ab/0x370 net/hsr/hsr_device.c:389
call_timer_fn+0x180/0x600 kernel/time/timer.c:1792
expire_timers kernel/time/timer.c:1843 [inline]
__run_timers kernel/time/timer.c:2408 [inline]
__run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2419
run_timer_base kernel/time/timer.c:2428 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2438
__do_softirq+0x2be/0x943 kernel/softirq.c:554
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:389
Code: 8b e8 14 f1 1a 0a 65 66 8b 05 54 5f aa 7e 66 85 c0 75 5d bf 01 00 00 00 e8 cd 7a 0b 00 e8 88 b3 42 00 fb 65 8b 05 18 5f aa 7e <85> c0 75 05 e8 b7 19 a7 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c
RSP: 0018:ffffc9000410fa00 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 1ffff92000821f44 RCX: ffffffff81720c2a
RDX: dffffc0000000000 RSI: ffffffff8baac1e0 RDI: ffffffff8bfed300
RBP: ffffc9000410fab0 R08: ffffffff92ce55df R09: 1ffffffff259cabb
R10: dffffc0000000000 R11: fffffbfff259cabc R12: dffffc0000000000
R13: 1ffff92000821f48 R14: ffffc9000410fa40 R15: 0000000000000201
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x30f/0x3b0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x365/0x610 net/batman-adv/network-coding.c:722
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa02/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f2/0x390 kernel/kthread.c:388
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
vkms_vblank_simulate: vblank timer overrun
----------------
Code disassembly (best guess):
0: 8b e8 mov %eax,%ebp
2: 14 f1 adc $0xf1,%al
4: 1a 0a sbb (%rdx),%cl
6: 65 66 8b 05 54 5f aa mov %gs:0x7eaa5f54(%rip),%ax # 0x7eaa5f62
d: 7e
e: 66 85 c0 test %ax,%ax
11: 75 5d jne 0x70
13: bf 01 00 00 00 mov $0x1,%edi
18: e8 cd 7a 0b 00 call 0xb7aea
1d: e8 88 b3 42 00 call 0x42b3aa
22: fb sti
23: 65 8b 05 18 5f aa 7e mov %gs:0x7eaa5f18(%rip),%eax # 0x7eaa5f42
* 2a: 85 c0 test %eax,%eax <-- trapping instruction
2c: 75 05 jne 0x33
2e: e8 b7 19 a7 ff call 0xffa719ea
33: 48 c7 44 24 20 0e 36 movq $0x45e0360e,0x20(%rsp)
3a: e0 45
3c: 49 rex.WB
3d: c7 .byte 0xc7
3e: 04 1c add $0x1c,%al