INFO: task syz.4.1613:5376 blocked for more than 123 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1613 state:D stack:0 pid:5376 tgid:5375 ppid:2543 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5945 [inline]
__schedule+0x1322/0x1df0 kernel/sched/core.c:7791
__schedule_loop kernel/sched/core.c:7872 [inline]
schedule+0xc6/0x240 kernel/sched/core.c:7887
schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common+0x359/0x630 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
rcu_barrier+0x415/0x530 kernel/rcu/tree.c:4657
flush_rcu_work+0x71/0x90 kernel/workqueue.c:4292
kvfree_rcu_barrier+0x248/0x2f0 kernel/rcu/tree.c:3955
kmem_cache_destroy+0x32/0x170 mm/slab_common.c:490
p9_client_destroy+0x42b/0x480 net/9p/client.c:1088
v9fs_session_init+0x13b7/0x1820 fs/9p/v9fs.c:490
v9fs_mount+0xd7/0xa00 fs/9p/vfs_super.c:122
legacy_get_tree+0x106/0x1b0 fs/fs_context.c:662
vfs_get_tree+0x9e/0x290 fs/super.c:1817
do_new_mount+0x251/0xb40 fs/namespace.c:3537
path_mount+0x688/0x1050 fs/namespace.c:3864
do_mount fs/namespace.c:3877 [inline]
__do_sys_mount fs/namespace.c:4087 [inline]
__se_sys_mount+0x2bd/0x480 fs/namespace.c:4064
__x64_sys_mount+0xc3/0xf0 fs/namespace.c:4064
x64_sys_call+0x2021/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f4029d8f6c9
RSP: 002b:00007f40287e3038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f4029fe5fa0 RCX: 00007f4029d8f6c9
RDX: 0000200000004380 RSI: 0000200000000300 RDI: 0000000000000000
RBP: 00007f4029e11f91 R08: 0000200000000500 R09: 0000000000000000
R10: 0000000001814800 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4029fe6038 R14: 00007f4029fe5fa0 R15: 00007fffb877b9b8
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xd8f/0xed0 kernel/hung_task.c:423
kthread+0x2ca/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5453 Comm: syz-executor Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__rcu_read_unlock+0x55/0xc0 kernel/rcu/tree_plugin.h:436
Code: c1 e8 03 42 0f b6 04 30 84 c0 75 33 ff 0b 75 1c 48 8d 9f c8 04 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 34 83 3b 00 <75> 0c 5b 41 5e 41 5f 5d e9 4e 70 20 04 cc e8 58 00 00 00 eb ed 89
RSP: 0018:ffffc90000007bd0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888107a83dc8 RCX: bb380fc37e724600
RDX: ffff88816df00b40 RSI: ffff88816df00c80 RDI: ffff888107a83900
RBP: ffffc90000007be8 R08: 00000000d826a1e6 R09: 000000000f1f5638
R10: 000000000000000f R11: ffffffff817457d0 R12: ffffffff87cc1508
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000020
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f22d2118740 CR3: 000000016835e000 CR4: 00000000003526b0
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:882 [inline]
process_backlog+0x45e/0xae0 net/core/dev.c:6219
__napi_poll+0xd3/0x610 net/core/dev.c:6869
napi_poll net/core/dev.c:6938 [inline]
net_rx_action+0x584/0xce0 net/core/dev.c:7060
handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
__do_softirq+0xf/0x16 kernel/softirq.c:659
do_softirq+0xa6/0x100 kernel/softirq.c:503
__local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x54/0x60 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
addrconf_ifdown+0x608/0x1940 net/ipv6/addrconf.c:3950
addrconf_notify+0x17a/0xea0 net/ipv6/addrconf.c:-1
notifier_call_chain+0x10b/0x2c0 kernel/notifier.c:93
raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461
call_netdevice_notifiers_info net/core/dev.c:2067 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2105 [inline]
call_netdevice_notifiers net/core/dev.c:2119 [inline]
unregister_netdevice_many_notify+0xe32/0x1bd0 net/core/dev.c:11501
unregister_netdevice_many net/core/dev.c:11563 [inline]
unregister_netdevice_queue+0x339/0x380 net/core/dev.c:11437
unregister_netdevice include/linux/netdevice.h:3165 [inline]
__tun_detach+0xca1/0x1460 drivers/net/tun.c:685
tun_detach drivers/net/tun.c:701 [inline]
tun_chr_close+0x93/0x150 drivers/net/tun.c:3517
__fput+0x1fb/0xa00 fs/file_table.c:429
____fput+0x20/0x30 fs/file_table.c:457
task_work_run+0x1e0/0x250 kernel/task_work.c:240
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x9bc/0x2630 kernel/exit.c:953
do_group_exit+0x22a/0x300 kernel/exit.c:1095
get_signal+0x139d/0x14f0 kernel/signal.c:2933
arch_do_signal_or_restart+0x96/0x720 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:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fec5d791503
Code: Unable to access opcode bytes at 0x7fec5d7914d9.
RSP: 002b:00007ffe20530828 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: 0000000000000044 RBX: 00007fec5e514620 RCX: 00007fec5d791503
RDX: 0000000000000044 RSI: 00007fec5e514670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffe20530844 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fec5e514670 R15: 0000000000000000
net_ratelimit: 104135 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:66:ff:24:53:cd:22, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
net_ratelimit: 122364 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:66:ff:24:53:cd:22, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)