============================================
WARNING: possible recursive locking detected
6.14.0-rc4-syzkaller-00859-gf77f12010f67 #0 Not tainted
--------------------------------------------
syz.1.1571/13170 is trying to acquire lock:
ffff8880504314c0 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff8880504314c0 (&br->multicast_lock){+.-.}-{3:3}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3521 [inline]
ffff8880504314c0 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3917 [inline]
ffff8880504314c0 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_rcv+0x3132/0x7ef0 net/bridge/br_multicast.c:3972
but task is already holding lock:
ffff88805d67d4c0 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88805d67d4c0 (&br->multicast_lock){+.-.}-{3:3}, 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
9 locks held by syz.1.1571/13170:
#0: ffff88807ddf15e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:190 [inline]
#0: ffff88807ddf15e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x162/0xd40 mm/mmap.c:1269
#1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: ___pte_offset_map+0x82/0x380 mm/pgtable-generic.c:287
#2: ffff88802ad5ed38 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffff88802ad5ed38 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x1ba/0x300 mm/pgtable-generic.c:402
#3: ffffffff8eb38f20 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#3: ffffffff8eb38f20 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:941 [inline]
#3: ffffffff8eb38f20 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid+0xf6/0x450 include/linux/mmzone.h:2067
#4: ffffc90000007be0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1786
#5: ffff88805d67d4c0 (&br->multicast_lock){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#5: ffff88805d67d4c0 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1905
#6: ffffffff8eb39000 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#6: ffffffff8eb39000 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:901 [inline]
#6: ffffffff8eb39000 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f4/0x3f40 net/core/dev.c:4576
#7: ffffffff8eb39000 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#7: ffffffff8eb39000 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:901 [inline]
#7: ffffffff8eb39000 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f4/0x3f40 net/core/dev.c:4576
#8: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#8: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#8: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x21d/0x1b40 net/bridge/br_device.c:50
stack backtrace:
CPU: 0 UID: 0 PID: 13170 Comm: syz.1.1571 Not tainted 6.14.0-rc4-syzkaller-00859-gf77f12010f67 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3039
check_deadlock kernel/locking/lockdep.c:3091 [inline]
validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3893
__lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
__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:3521 [inline]
br_multicast_ipv6_rcv net/bridge/br_multicast.c:3917 [inline]
br_multicast_rcv+0x3132/0x7ef0 net/bridge/br_multicast.c:3972
br_dev_xmit+0xb94/0x1b40 net/bridge/br_device.c:96
__netdev_start_xmit include/linux/netdevice.h:5187 [inline]
netdev_start_xmit include/linux/netdevice.h:5196 [inline]
xmit_one net/core/dev.c:3801 [inline]
dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3817
__dev_queue_xmit+0x1b73/0x3f40 net/core/dev.c:4651
dev_queue_xmit include/linux/netdevice.h:3343 [inline]
vlan_dev_hard_start_xmit+0x36c/0x5f0 net/8021q/vlan_dev.c:125
__netdev_start_xmit include/linux/netdevice.h:5187 [inline]
netdev_start_xmit include/linux/netdevice.h:5196 [inline]
xmit_one net/core/dev.c:3801 [inline]
dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3817
__dev_queue_xmit+0x1b73/0x3f40 net/core/dev.c:4651
dev_queue_xmit include/linux/netdevice.h:3343 [inline]
br_dev_queue_push_xmit+0x726/0x900 net/bridge/br_forward.c:53
NF_HOOK include/linux/netfilter.h:314 [inline]
__br_multicast_send_query+0x2fb8/0x4810 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+0x187/0x650 kernel/time/timer.c:1789
expire_timers kernel/time/timer.c:1840 [inline]
__run_timers kernel/time/timer.c:2414 [inline]
__run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2426
run_timer_base kernel/time/timer.c:2435 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445
handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
__do_softirq kernel/softirq.c:595 [inline]
invoke_softirq kernel/softirq.c:435 [inline]
__irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662
irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
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:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:123 [inline]
RIP: 0010:lock_release+0x191/0xa30 kernel/locking/lockdep.c:5868
Code: 00 00 4c 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 d1 24 8c 00 4c 89 6c 24 50 48 c7 84 24 b0 00 00 00 00 00 00 00 9c <8f> 84 24 b0 00 00 00 42 80 3c 3b 00 74 08 4c 89 f7 e8 b9 23 8c 00
RSP: 0018:ffffc90003457098 EFLAGS: 00000246
RAX: ffffffff940bb710 RBX: 1ffff9200068ae2a RCX: ffffffff819cda20
RDX: 0000000000000000 RSI: ffffffff8c80eea0 RDI: ffffffff8c80ee60
RBP: ffffc900034571d8 R08: ffffffff903cf777 R09: 1ffffffff2079eee
R10: dffffc0000000000 R11: fffffbfff2079eef R12: 1ffff9200068ae20
R13: ffffffff8234ee86 R14: ffffc90003457150 R15: dffffc0000000000
rcu_lock_release include/linux/rcupdate.h:347 [inline]
rcu_read_unlock_sched include/linux/rcupdate.h:962 [inline]
pfn_valid+0x3eb/0x450 include/linux/mmzone.h:2077
page_table_check_clear+0x1e/0x550 mm/page_table_check.c:70
get_and_clear_full_ptes include/linux/pgtable.h:712 [inline]
zap_present_folio_ptes mm/memory.c:1511 [inline]
zap_present_ptes mm/memory.c:1596 [inline]
do_zap_pte_range mm/memory.c:1698 [inline]
zap_pte_range mm/memory.c:1742 [inline]
zap_pmd_range mm/memory.c:1834 [inline]
zap_pud_range mm/memory.c:1863 [inline]
zap_p4d_range mm/memory.c:1884 [inline]
unmap_page_range+0x33fa/0x4510 mm/memory.c:1905
unmap_vmas+0x3cc/0x5f0 mm/memory.c:1995
exit_mmap+0x283/0xd40 mm/mmap.c:1284
__mmput+0x115/0x420 kernel/fork.c:1356
exit_mm+0x220/0x310 kernel/exit.c:570
do_exit+0x9ad/0x28e0 kernel/exit.c:925
do_group_exit+0x207/0x2c0 kernel/exit.c:1087
get_signal+0x168c/0x1720 kernel/signal.c:3036
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7dae58d169
Code: Unable to access opcode bytes at 0x7f7dae58d13f.
RSP: 002b:00007f7daf4b3038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 000000000000004c RBX: 00007f7dae7a6080 RCX: 00007f7dae58d169
RDX: 0000000000000000 RSI: 0000400000000280 RDI: 000000000000000f
RBP: 00007f7dae60e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7dae7a6080 R15: 00007ffede1bb068
</TASK>
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 4c 89 f3 mov %r14,%rbx
5: 48 c1 eb 03 shr $0x3,%rbx
9: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1)
e: 74 08 je 0x18
10: 4c 89 f7 mov %r14,%rdi
13: e8 d1 24 8c 00 call 0x8c24e9
18: 4c 89 6c 24 50 mov %r13,0x50(%rsp)
1d: 48 c7 84 24 b0 00 00 movq $0x0,0xb0(%rsp)
24: 00 00 00 00 00
29: 9c pushf
* 2a: 8f 84 24 b0 00 00 00 pop 0xb0(%rsp) <-- trapping instruction
31: 42 80 3c 3b 00 cmpb $0x0,(%rbx,%r15,1)
36: 74 08 je 0x40
38: 4c 89 f7 mov %r14,%rdi
3b: e8 b9 23 8c 00 call 0x8c23f9