INFO: task syz.2.511:1655 blocked for more than 123 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.511 state:D stack:0 pid:1655 tgid:1646 ppid:296 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:6027 [inline]
__schedule+0x14ce/0x2100 kernel/sched/core.c:7894
__schedule_loop kernel/sched/core.c:7975 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7990
schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common+0x369/0x650 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
rcu_barrier+0x415/0x540 kernel/rcu/tree.c:4657
netdev_run_todo+0x118/0xce0 net/core/dev.c:10912
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
tun_detach drivers/net/tun.c:704 [inline]
tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520
__fput+0x1fb/0xa00 fs/file_table.c:429
____fput+0x20/0x30 fs/file_table.c:457
task_work_run+0x1e5/0x260 kernel/task_work.c:246
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x9ad/0x2720 kernel/exit.c:954
do_group_exit+0x229/0x2f0 kernel/exit.c:1096
get_signal+0x1398/0x14e0 kernel/signal.c:2933
arch_do_signal_or_restart+0xbc/0x760 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+0x57/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fa17359ce59
RSP: 002b:00007fa1744350e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fa173816098 RCX: 00007fa17359ce59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa173816098
RBP: 00007fa173816090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa173816128 R14: 00007fffe88dc6a0 R15: 00007fffe88dc788
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 471281939cd7bfdfff4c6b6074d5d68627c837ba
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2ba/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+0xdad/0xf00 kernel/hung_task.c:423
kthread+0x2c9/0x370 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: 1719 Comm: syz-executor Not tainted syzkaller #0 471281939cd7bfdfff4c6b6074d5d68627c837ba
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:stack_trace_consume_entry+0x13b/0x2a0 kernel/stacktrace.c:95
Code: d9 4d 89 e0 4c 89 f2 48 8b 75 c0 49 89 37 41 8b 18 41 0f b6 44 15 00 84 c0 0f 85 42 01 00 00 41 3b 19 0f 92 c0 48 83 c4 20 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 97 04 35 04 cc 44 89 c1 80 e1 07 80
RSP: 0018:ffffc90000f2f3f8 EFLAGS: 00000286
RAX: 0000000000000001 RBX: ffffc90000f2f4e0 RCX: 0000000000f2f400
RDX: dffffc0000000000 RSI: ffffffff81d6c5da RDI: ffffc90000f2f4e0
RBP: ffffc90000f2f418 R08: ffffc90000f2f4f0 R09: ffffc90000f2f4e8
R10: 0000000000000002 R11: ffffffff8175ee80 R12: ffffc90000f2f4ec
R13: 1ffff920001e5e9d R14: ffffc90000f2f5a0 R15: ffffc90000f2f5b0
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005626400ba1f0 CR3: 0000000102358000 CR4: 00000000003526b0
Call Trace:
arch_stack_walk+0x129/0x170 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
save_stack+0x125/0x240 mm/page_owner.c:174
__reset_page_owner+0x79/0x450 mm/page_owner.c:315
reset_page_owner include/linux/page_owner.h:28 [inline]
free_pages_prepare mm/page_alloc.c:1390 [inline]
free_unref_page+0xbcf/0xf80 mm/page_alloc.c:2876
__free_pages+0x6b/0x3b0 mm/page_alloc.c:5402
vfree+0x3ea/0x5b0 mm/vmalloc.c:3408
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x2c/0x70 kernel/kcov.c:535
__fput+0x1fb/0xa00 fs/file_table.c:429
____fput+0x20/0x30 fs/file_table.c:457
task_work_run+0x1e5/0x260 kernel/task_work.c:246
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x9ad/0x2720 kernel/exit.c:954
do_group_exit+0x229/0x2f0 kernel/exit.c:1096
get_signal+0x1398/0x14e0 kernel/signal.c:2933
arch_do_signal_or_restart+0xbc/0x760 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+0x57/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f81cf357fd7
Code: Unable to access opcode bytes at 0x7f81cf357fad.
RSP: 002b:00007fffbbd7e140 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: fffffffffffffffe RBX: 00005555742a3500 RCX: 00007f81cf357fd7
RDX: 0000000000080001 RSI: 00007f81cf44d939 RDI: ffffffffffffff9c
RBP: 00007f81cf44d939 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007fffbbd7e200 R14: 00007fffbbd7e948 R15: 0000000000000000
net_ratelimit: 143393 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:4a:d0:2a:37:16:ab, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)