============================================
WARNING: possible recursive locking detected
6.8.0-syzkaller-08073-g480e035fc4c7 #0 Not tainted
--------------------------------------------
kworker/u8:5/81 is trying to acquire lock:
ffff8880240413e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff8880240413e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline]
ffff8880240413e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline]
ffff8880240413e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974
but task is already holding lock:
ffff8880605e53e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff8880605e53e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1905
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&br->multicast_lock);
lock(&br->multicast_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
8 locks held by kworker/u8:5/81:
#0: ffff88802a584148 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
#0: ffff88802a584148 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
#1: ffffc9000234fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
#1: ffffc9000234fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
#2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
#2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: batadv_nc_worker+0xcb/0x610 net/batman-adv/network-coding.c:719
#3: ffffc90000a08c00 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789
#4: ffff8880605e53e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#4: ffff8880605e53e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1905
#5: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#5: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
#5: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260
#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
stack backtrace:
CPU: 1 PID: 81 Comm: kworker/u8:5 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
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 include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline]
br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline]
br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974
br_dev_xmit+0xb17/0x1a10 net/bridge/br_device.c:90
__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+0x26a/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]
vlan_dev_hard_start_xmit+0x36c/0x5f0 net/8021q/vlan_dev.c:125
__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+0x26a/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 include/linux/netfilter.h:314 [inline]
__br_multicast_send_query+0x2ecb/0x4750 net/bridge/br_multicast.c:1809
br_multicast_send_query+0x4ee/0x6b0 net/bridge/br_multicast.c:1888
br_multicast_port_query_expired+0x2d4/0x3b0 net/bridge/br_multicast.c:1913
call_timer_fn+0x17e/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+0x2bc/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:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:206
Code: 8b 3d 6c fc 1b 0c 48 89 de 5b e9 23 fb 57 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 80 d0 03 00 65 8b 15 20 db 6e 7e f7 c2 00 01 ff 00
RSP: 0018:ffffc9000234fb50 EFLAGS: 00000202
RAX: ffffffff8b407ae0 RBX: 0000000000000001 RCX: ffff888017f50000
RDX: ffff888017f50000 RSI: ffffffff8bfed340 RDI: ffffffff8bfed300
RBP: 0000000000000000 R08: ffffffff8b407ace R09: 1ffffffff259c2a0
R10: dffffc0000000000 R11: fffffbfff259c2a1 R12: ffff888060378ca0
R13: 000000000000034b R14: ffff88801209b980 R15: dffffc0000000000
rcu_read_unlock include/linux/rcupdate.h:779 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x210/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/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 3d 6c fc 1b 0c mov 0xc1bfc6c(%rip),%edi # 0xc1bfc72
6: 48 89 de mov %rbx,%rsi
9: 5b pop %rbx
a: e9 23 fb 57 00 jmp 0x57fb32
f: 0f 1f 00 nopl (%rax)
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: 90 nop
1a: 90 nop
1b: 90 nop
1c: 90 nop
1d: 90 nop
1e: 90 nop
1f: 90 nop
20: 90 nop
21: 90 nop
22: f3 0f 1e fa endbr64
26: 48 8b 04 24 mov (%rsp),%rax
* 2a: 65 48 8b 0c 25 80 d0 mov %gs:0x3d080,%rcx <-- trapping instruction
31: 03 00
33: 65 8b 15 20 db 6e 7e mov %gs:0x7e6edb20(%rip),%edx # 0x7e6edb5a
3a: f7 c2 00 01 ff 00 test $0xff0100,%edx