============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz-executor/13284 is trying to acquire lock:
ffff88807b1e5508 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88807b1e5508 (&br->multicast_lock){+.-.}-{3:3}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3592 [inline]
ffff88807b1e5508 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3988 [inline]
ffff88807b1e5508 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_rcv+0x2d0b/0x74b0 net/bridge/br_multicast.c:4043
but task is already holding lock:
ffff88807ca1d508 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88807ca1d508 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_port_query_expired+0x62/0x370 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
7 locks held by syz-executor/13284:
#0: ffff88807dfcfb50 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline]
#0: ffff88807dfcfb50 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#1: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#1: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
#1: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
#2: ffffc90000007be0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0 kernel/time/timer.c:1744
#3: ffff88807ca1d508 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#3: ffff88807ca1d508 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_port_query_expired+0x62/0x370 net/bridge/br_multicast.c:1905
#4: ffffffff8e13d340 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#4: ffffffff8e13d340 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
#4: ffffffff8e13d340 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x284/0x3740 net/core/dev.c:4728
#5: ffffffff8e13d340 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#5: ffffffff8e13d340 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
#5: ffffffff8e13d340 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x284/0x3740 net/core/dev.c:4728
#6: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#6: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#6: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x185/0x1840 net/bridge/br_device.c:52
stack backtrace:
CPU: 0 UID: 0 PID: 13284 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3041
check_deadlock kernel/locking/lockdep.c:3093 [inline]
validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3895
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__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:3592 [inline]
br_multicast_ipv6_rcv net/bridge/br_multicast.c:3988 [inline]
br_multicast_rcv+0x2d0b/0x74b0 net/bridge/br_multicast.c:4043
br_dev_xmit+0xaf7/0x1840 net/bridge/br_device.c:98
__netdev_start_xmit include/linux/netdevice.h:5248 [inline]
netdev_start_xmit include/linux/netdevice.h:5257 [inline]
xmit_one net/core/dev.c:3845 [inline]
dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861
__dev_queue_xmit+0x172a/0x3740 net/core/dev.c:4803
dev_queue_xmit_accel include/linux/netdevice.h:3371 [inline]
macvlan_queue_xmit drivers/net/macvlan.c:557 [inline]
macvlan_start_xmit+0x46d/0x6e0 drivers/net/macvlan.c:581
__netdev_start_xmit include/linux/netdevice.h:5248 [inline]
netdev_start_xmit include/linux/netdevice.h:5257 [inline]
xmit_one net/core/dev.c:3845 [inline]
dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861
__dev_queue_xmit+0x172a/0x3740 net/core/dev.c:4803
dev_queue_xmit include/linux/netdevice.h:3365 [inline]
br_dev_queue_push_xmit+0x6c5/0x890 net/bridge/br_forward.c:53
NF_HOOK include/linux/netfilter.h:318 [inline]
__br_multicast_send_query+0x2ea1/0x4580 net/bridge/br_multicast.c:1809
br_multicast_send_query+0x4d6/0x680 net/bridge/br_multicast.c:1888
br_multicast_port_query_expired+0x2a4/0x370 net/bridge/br_multicast.c:1913
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 fb ac f3 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000c956f58 EFLAGS: 00000206
RAX: b9605ba17f675900 RBX: 0000000000000000 RCX: b9605ba17f675900
RDX: 0000000000000000 RSI: ffffffff8d9d182c RDI: ffffffff8bc077e0
RBP: ffffffff8173cd25 R08: 0000000000000000 R09: ffffffff8173cd25
R10: ffffc9000c957118 R11: ffffffff81ac6cd0 R12: 0000000000000002
R13: ffffffff8e13d2e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4955 [inline]
slab_alloc_node mm/slub.c:5265 [inline]
kmem_cache_alloc_lru_noprof+0x35d/0x6d0 mm/slub.c:5284
__d_alloc+0x36/0x7a0 fs/dcache.c:1690
d_alloc_parallel+0xe1/0x1610 fs/dcache.c:2549
__lookup_slow+0x116/0x3d0 fs/namei.c:1801
lookup_slow+0x53/0x70 fs/namei.c:1833
walk_component+0x2d2/0x400 fs/namei.c:2151
link_path_walk+0x75b/0xea0 fs/namei.c:2516
path_openat+0x28c/0x3830 fs/namei.c:4130
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda7658d710
Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 69 95 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 bc 95 02 00 8b 44
RSP: 002b:00007ffd58ea9bd0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000080001 RCX: 00007fda7658d710
RDX: 0000000000080001 RSI: 00007fda76613818 RDI: 00000000ffffff9c
RBP: 00007fda76613818 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007ffd58ea9c70 R14: 000000000004f7f8 R15: 00007ffd58eaa1e0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 9c pushf
5: 8f 44 24 30 pop 0x30(%rsp)
9: f7 44 24 30 00 02 00 testl $0x200,0x30(%rsp)
10: 00
11: 0f 85 cd 00 00 00 jne 0xe4
17: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp)
1e: 00
1f: 74 01 je 0x22
21: fb sti
22: 65 48 8b 05 fb ac f3 mov %gs:0x10f3acfb(%rip),%rax # 0x10f3ad25
29: 10
* 2a: 48 3b 44 24 58 cmp 0x58(%rsp),%rax <-- trapping instruction
2f: 0f 85 f2 00 00 00 jne 0x127
35: 48 83 c4 60 add $0x60,%rsp
39: 5b pop %rbx
3a: 41 5c pop %r12
3c: 41 5d pop %r13
3e: 41 5e pop %r14