============================================
WARNING: possible recursive locking detected
6.8.0-syzkaller-08073-g480e035fc4c7 #0 Not tainted
--------------------------------------------
syz-executor.1/20384 is trying to acquire lock:
ffff88805bf6d3e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88805bf6d3e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline]
ffff88805bf6d3e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline]
ffff88805bf6d3e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974
but task is already holding lock:
ffff8880583993e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff8880583993e0 (&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 syz-executor.1/20384:
#0: ffff888055c2b210 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline]
#0: ffff888055c2b210 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
#0: ffff888055c2b210 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1421
#1: ffffffff8f3efbd0 ((netlink_chain).rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x53/0x90 kernel/notifier.c:387
#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: net_generic include/net/netns/generic.h:45 [inline]
#2: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: nfnl_queue_pernet+0x23/0x240 net/netfilter/nfnetlink_queue.c:95
#3: ffffc90000a08c00 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789
#4: ffff8880583993e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#4: ffff8880583993e0 (&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: 20384 Comm: syz-executor.1 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
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:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:103 [inline]
RIP: 0010:lock_release+0x141/0x9d0 kernel/locking/lockdep.c:5770
Code: 42 0f b6 04 38 84 c0 0f 85 c3 05 00 00 83 3b 00 0f 85 f1 04 00 00 4c 8d b4 24 b0 00 00 00 4c 89 f3 48 c1 eb 03 42 80 3c 3b 00 <74> 08 4c 89 f7 e8 45 84 86 00 4c 89 6c 24 50 48 c7 84 24 b0 00 00
RSP: 0018:ffffc90003fcfa60 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff920007f9f62 RCX: ffffffff8171c080
RDX: 0000000000000000 RSI: ffffffff8bfed340 RDI: ffffffff8bfed300
RBP: ffffc90003fcfba0 R08: ffffffff8f872cef R09: 1ffffffff1f0e59d
R10: dffffc0000000000 R11: fffffbfff1f0e59e R12: 1ffff920007f9f58
R13: ffffffff89908943 R14: ffffc90003fcfb10 R15: dffffc0000000000
rcu_lock_release include/linux/rcupdate.h:308 [inline]
rcu_read_unlock include/linux/rcupdate.h:783 [inline]
net_generic include/net/netns/generic.h:48 [inline]
nfnl_queue_pernet+0x1ef/0x240 net/netfilter/nfnetlink_queue.c:95
nfqnl_rcv_nl_event+0x46/0x2c0 net/netfilter/nfnetlink_queue.c:1170
notifier_call_chain+0x18f/0x3b0 kernel/notifier.c:93
blocking_notifier_call_chain+0x69/0x90 kernel/notifier.c:388
netlink_release+0x11a6/0x1b10 net/netlink/af_netlink.c:791
__sock_release net/socket.c:659 [inline]
sock_close+0xbc/0x240 net/socket.c:1421
__fput+0x429/0x8a0 fs/file_table.c:422
__do_sys_close fs/open.c:1556 [inline]
__se_sys_close fs/open.c:1541 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1541
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f4cc8e7cc9a
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24
RSP: 002b:00007f4cc90cfb10 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f4cc8e7cc9a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000032 R08: 0000001b2f420000 R09: 0000000000000065
R10: 000000008136099b R11: 0000000000000293 R12: 00007f4cc8a00d08
R13: ffffffffffffffff R14: 00007f4cc8a00000 R15: 0000000000087170
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
----------------
Code disassembly (best guess):
0: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax
5: 84 c0 test %al,%al
7: 0f 85 c3 05 00 00 jne 0x5d0
d: 83 3b 00 cmpl $0x0,(%rbx)
10: 0f 85 f1 04 00 00 jne 0x507
16: 4c 8d b4 24 b0 00 00 lea 0xb0(%rsp),%r14
1d: 00
1e: 4c 89 f3 mov %r14,%rbx
21: 48 c1 eb 03 shr $0x3,%rbx
25: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1)
* 2a: 74 08 je 0x34 <-- trapping instruction
2c: 4c 89 f7 mov %r14,%rdi
2f: e8 45 84 86 00 call 0x868479
34: 4c 89 6c 24 50 mov %r13,0x50(%rsp)
39: 48 rex.W
3a: c7 .byte 0xc7
3b: 84 24 b0 test %ah,(%rax,%rsi,4)