============================================
WARNING: possible recursive locking detected
6.8.0-syzkaller-05204-g237bb5f7f7f5 #0 Not tainted
--------------------------------------------
syz-executor.0/15484 is trying to acquire lock:
ffff88802d4653e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88802d4653e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline]
ffff88802d4653e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline]
ffff88802d4653e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974
but task is already holding lock:
ffff888066ed13e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff888066ed13e0 (&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
9 locks held by syz-executor.0/15484:
#0: ffffffff8f379390 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:501
#1: ffffffff8f385a08 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x213/0x710 net/ipv4/ip_tunnel.c:1116
#2: ffff888015ace948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_add_one+0x9a/0x8b0 fs/kernfs/dir.c:769
#3: ffff888015ace9e0 (&root->kernfs_iattr_rwsem){++++}-{3:3}, at: kernfs_add_one+0x3c8/0x8b0 fs/kernfs/dir.c:791
#4: ffffc90000007c00 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789
#5: ffff888066ed13e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#5: ffff888066ed13e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1905
#6: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#6: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
#6: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260
#7: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#7: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
#7: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260
#8: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#8: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#8: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x1b9/0x1a10 net/bridge/br_device.c:44
stack backtrace:
CPU: 0 PID: 15484 Comm: syz-executor.0 Not tainted 6.8.0-syzkaller-05204-g237bb5f7f7f5 #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+0x1e7/0x2e0 lib/dump_stack.c:106
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:lock_acquire+0x25b/0x530 kernel/locking/lockdep.c:5758
Code: 2b 00 74 08 4c 89 f7 e8 13 99 86 00 f6 44 24 61 02 0f 85 8e 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc900031e7260 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff9200063ce58 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8baad3a0 RDI: ffffffff8bfec660
RBP: ffffc900031e73c0 R08: ffffffff92cc750f R09: 1ffffffff2598ea1
R10: dffffc0000000000 R11: fffffbfff2598ea2 R12: 1ffff9200063ce54
R13: dffffc0000000000 R14: ffffc900031e72c0 R15: 0000000000000246
down_write+0x3a/0x50 kernel/locking/rwsem.c:1579
kernfs_add_one+0x3c8/0x8b0 fs/kernfs/dir.c:791
kernfs_create_dir_ns+0xd9/0x120 fs/kernfs/dir.c:1062
internal_create_group+0x2a7/0xf20 fs/sysfs/group.c:138
internal_create_groups fs/sysfs/group.c:192 [inline]
sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:218
device_add_groups drivers/base/core.c:2741 [inline]
device_add_attrs+0x199/0x600 drivers/base/core.c:2861
device_add+0x57d/0xca0 drivers/base/core.c:3593
netdev_register_kobject+0x17e/0x320 net/core/net-sysfs.c:2136
register_netdevice+0x1208/0x1a20 net/core/dev.c:10274
__ip_tunnel_create+0x2b4/0x380 net/ipv4/ip_tunnel.c:266
ip_tunnel_init_net+0x223/0x710 net/ipv4/ip_tunnel.c:1117
ops_init+0x352/0x610 net/core/net_namespace.c:136
setup_net+0x515/0xca0 net/core/net_namespace.c:340
copy_net_ns+0x4e4/0x7b0 net/core/net_namespace.c:505
create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x619/0xc10 kernel/fork.c:3322
__do_sys_unshare kernel/fork.c:3393 [inline]
__se_sys_unshare kernel/fork.c:3391 [inline]
__x64_sys_unshare+0x38/0x40 kernel/fork.c:3391
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fd3f167f507
Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 10 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff62694138 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fd3f167f507
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007fff62694210 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff626947f8
R13: 0000000000000003 R14: 00007fd3f17ac9d8 R15: 000000000000000c
----------------
Code disassembly (best guess):
0: 2b 00 sub (%rax),%eax
2: 74 08 je 0xc
4: 4c 89 f7 mov %r14,%rdi
7: e8 13 99 86 00 call 0x86991f
c: f6 44 24 61 02 testb $0x2,0x61(%rsp)
11: 0f 85 8e 01 00 00 jne 0x1a5
17: 41 f7 c7 00 02 00 00 test $0x200,%r15d
1e: 74 01 je 0x21
20: fb sti
21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp)
28: e0 45
* 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction
31: 00 00
33: 43 c7 44 25 09 00 00 movl $0x0,0x9(%r13,%r12,1)
3a: 00 00
3c: 43 rex.XB
3d: c7 .byte 0xc7
3e: 44 rex.R
3f: 25 .byte 0x25