============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.3.7123/32594 is trying to acquire lock:
ffff8880a39355e0 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
ffff8880a39355e0 (&br->multicast_lock){+.-.}-{3:3}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3581 [inline]
ffff8880a39355e0 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3977 [inline]
ffff8880a39355e0 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_rcv+0x2dda/0x7640 net/bridge/br_multicast.c:4032
but task is already holding lock:
ffff88804f3895e0 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
ffff88804f3895e0 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_port_query_expired net/bridge/br_multicast.c:1901 [inline]
ffff88804f3895e0 (&br->multicast_lock){+.-.}-{3:3}, at: br_ip6_multicast_port_query_expired+0x6b/0x380 net/bridge/br_multicast.c:1929
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
10 locks held by syz.3.7123/32594:
#0: ffffffff8fdd13c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8fdd13c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8fdd13c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4122
#1: ffffffff8e94f1c0 (console_lock){+.+.}-{0:0}, at: _printk+0xdd/0x130 kernel/printk/printk.c:2504
#2: ffffffff8e836a58 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:305 [inline]
#2: ffffffff8e836a58 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:428 [inline]
#2: ffffffff8e836a58 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:291 [inline]
#2: ffffffff8e836a58 (console_srcu){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3246 [inline]
#2: ffffffff8e836a58 (console_srcu){....}-{0:0}, at: console_flush_all+0x123/0xb20 kernel/printk/printk.c:3343
#3: ffffc90000a08cc0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5e0 kernel/time/timer.c:1745
#4: ffff88804f3895e0 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
#4: ffff88804f3895e0 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_port_query_expired net/bridge/br_multicast.c:1901 [inline]
#4: ffff88804f3895e0 (&br->multicast_lock){+.-.}-{3:3}, at: br_ip6_multicast_port_query_expired+0x6b/0x380 net/bridge/br_multicast.c:1929
#5: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#5: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#5: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4792
#6: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#6: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#6: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4792
#7: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#7: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#7: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: bond_start_xmit+0xb4/0x1900 drivers/net/bonding/bond_main.c:5591
#8: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#8: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#8: ffffffff8e95ce00 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4792
#9: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#9: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#9: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x193/0x1990 net/bridge/br_device.c:52
stack backtrace:
CPU: 1 UID: 0 PID: 32594 Comm: syz.3.7123 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 include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
spin_lock include/linux/spinlock.h:342 [inline]
br_ip6_multicast_query net/bridge/br_multicast.c:3581 [inline]
br_multicast_ipv6_rcv net/bridge/br_multicast.c:3977 [inline]
br_multicast_rcv+0x2dda/0x7640 net/bridge/br_multicast.c:4032
br_dev_xmit+0xb67/0x1990 net/bridge/br_device.c:98
__netdev_start_xmit include/linux/netdevice.h:5379 [inline]
netdev_start_xmit include/linux/netdevice.h:5388 [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:4871
__bond_start_xmit drivers/net/bonding/bond_main.c:-1 [inline]
bond_start_xmit+0xd5c/0x1900 drivers/net/bonding/bond_main.c:5593
__netdev_start_xmit include/linux/netdevice.h:5379 [inline]
netdev_start_xmit include/linux/netdevice.h:5388 [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:4871
dev_queue_xmit_accel include/linux/netdevice.h:3435 [inline]
macvlan_queue_xmit drivers/net/macvlan.c:571 [inline]
macvlan_start_xmit+0x3ba/0x600 drivers/net/macvlan.c:595
__netdev_start_xmit include/linux/netdevice.h:5379 [inline]
netdev_start_xmit include/linux/netdevice.h:5388 [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:4871
dev_queue_xmit include/linux/netdevice.h:3429 [inline]
br_dev_queue_push_xmit+0x370/0x4b0 net/bridge/br_forward.c:53
NF_HOOK include/linux/netfilter.h:318 [inline]
__br_multicast_send_query+0x3100/0x4840 net/bridge/br_multicast.c:1805
br_multicast_send_query+0x509/0x6b0 net/bridge/br_multicast.c:1884
br_multicast_port_query_expired net/bridge/br_multicast.c:1909 [inline]
br_ip6_multicast_port_query_expired+0x2b5/0x380 net/bridge/br_multicast.c:1929
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:console_flush_one_record arch/x86/include/asm/irqflags.h:-1 [inline]
RIP: 0010:console_flush_all+0x801/0xb20 kernel/printk/printk.c:3343
Code: ff ff e8 02 eb 20 00 90 0f 0b 90 e9 85 fc ff ff e8 f4 ea 20 00 e8 af 8b 05 0a 48 85 db 74 c0 e8 e5 ea 20 00 fb 48 8b 5c 24 08 <48> 8b 44 24 20 42 80 3c 20 00 4c 8b 74 24 18 74 08 4c 89 f7 e8 a6
RSP: 0018:ffffc90006bfe580 EFLAGS: 00000246
RAX: ffffffff81a4d97b RBX: ffffc90006bfe6e0 RCX: 0000000000080000
RDX: ffffc90010b5e000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90006bfe690 R08: ffffffff90311df7 R09: 1ffffffff20623be
R10: dffffc0000000000 R11: fffffbfff20623bf R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff8f21a120
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
vlan_vid0_add net/8021q/vlan.c:370 [inline]
vlan_device_event+0x1cbc/0x1f10 net/8021q/vlan.c:413
notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
call_netdevice_notifiers net/core/dev.c:2301 [inline]
__dev_notify_flags+0x1a9/0x310 net/core/dev.c:9798
netif_change_flags+0xe8/0x1a0 net/core/dev.c:9827
do_setlink+0xfa5/0x45a0 net/core/rtnetlink.c:3194
rtnl_group_changelink net/core/rtnetlink.c:3827 [inline]
__rtnl_newlink net/core/rtnetlink.c:3995 [inline]
rtnl_newlink+0x14ca/0x1bb0 net/core/rtnetlink.c:4123
rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7009
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe2d5f9ce59
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:00007fe2d6e32028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe2d6216090 RCX: 00007fe2d5f9ce59
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 000000000000000b
RBP: 00007fe2d6032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe2d6216128 R14: 00007fe2d6216090 R15: 00007ffe4eadf9b8
----------------
Code disassembly (best guess), 1 bytes skipped:
0: ff ljmp (bad)
1: e8 02 eb 20 00 call 0x20eb08
6: 90 nop
7: 0f 0b ud2
9: 90 nop
a: e9 85 fc ff ff jmp 0xfffffc94
f: e8 f4 ea 20 00 call 0x20eb08
14: e8 af 8b 05 0a call 0xa058bc8
19: 48 85 db test %rbx,%rbx
1c: 74 c0 je 0xffffffde
1e: e8 e5 ea 20 00 call 0x20eb08
23: fb sti
24: 48 8b 5c 24 08 mov 0x8(%rsp),%rbx
* 29: 48 8b 44 24 20 mov 0x20(%rsp),%rax <-- trapping instruction
2e: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
33: 4c 8b 74 24 18 mov 0x18(%rsp),%r14
38: 74 08 je 0x42
3a: 4c 89 f7 mov %r14,%rdi
3d: e8 .byte 0xe8
3e: a6 cmpsb %es:(%rdi),%ds:(%rsi)