INFO: task kworker/u8:0:12 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack:23240 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events_unbound linkwatch_event
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
linkwatch_event+0xe/0x60 net/core/link_watch.c:313
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.1.691:8274 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.691 state:D stack:24936 pid:8274 tgid:8274 ppid:5645 task_flags:0x400040 flags:0x08080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
raw_release+0x1bb/0x9f0 net/can/raw.c:430
__sock_release net/socket.c:710 [inline]
sock_close+0xad/0x220 net/socket.c:1501
__fput+0x418/0xa50 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
__do_fast_syscall_32+0x45b/0x6f0 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf705f0ec
RSP: 002b:00000000f757fb1c EFLAGS: 00000206 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
INFO: task syz.5.693:8280 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.693 state:D stack:24760 pid:8280 tgid:8280 ppid:6008 task_flags:0x400040 flags:0x08080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
tun_detach drivers/net/tun.c:634 [inline]
tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3442
__fput+0x418/0xa50 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
__do_fast_syscall_32+0x45b/0x6f0 arch/x86/entry/syscall_32.c:310
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fc30ec
RSP: 002b:00000000f75afb1c EFLAGS: 00000206 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4981 Comm: klogd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:nf_hook_slow+0x125/0x220 net/netfilter/core.c:-1
Code: 8b 74 24 10 44 89 e2 89 e9 e8 f7 67 00 00 89 c3 bf 01 00 00 00 89 c6 e8 69 9b 00 f8 83 fb 01 0f 85 c1 00 00 00 e8 1b 97 00 f8 <48> bd 00 00 00 00 00 fc ff df 41 0f b6 04 2e 84 c0 75 21 49 ff c4
RSP: 0018:ffffc90000007130 EFLAGS: 00000246
RAX: ffffffff89c55eca RBX: 0000000000000001 RCX: ffff88807c58be00
RDX: 0000000000000100 RSI: ffffffff8fe4e0e0 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffff88807c58be00 R09: 0000000000000004
R10: 0000000000000003 R11: 0000000000000100 R12: 0000000000000002
R13: ffff888059a69328 R14: 1ffff1100b34d260 R15: ffff888059a69330
FS: 00007fad3f729c80(0000) GS:ffff88812528f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d40cb98850 CR3: 000000007ca10000 CR4: 00000000003526f0
Call Trace:
nf_hook+0x22a/0x3a0 include/linux/netfilter.h:273
NF_HOOK_COND include/linux/netfilter.h:306 [inline]
ip_output+0x269/0x450 net/ipv4/ip_output.c:438
synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:489
nft_synproxy_eval_v4+0x37b/0x530 net/netfilter/nft_synproxy.c:60
nft_synproxy_do_eval+0x335/0x550 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1ad0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6202 [inline]
__netif_receive_skb net/core/dev.c:6315 [inline]
process_backlog+0xa34/0x1860 net/core/dev.c:6666
__napi_poll+0xaa/0x330 net/core/dev.c:7733
napi_poll net/core/dev.c:7796 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:7953
handle_softirqs+0x225/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x1ad/0x7a0 net/core/skbuff.c:699
alloc_skb include/linux/skbuff.h:1385 [inline]
alloc_skb_with_frags+0xc6/0x760 net/core/skbuff.c:6768
sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:3007
unix_dgram_sendmsg+0x4da/0x17b0 net/unix/af_unix.c:2141
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
__sys_sendto+0x626/0x6c0 net/socket.c:2252
__do_sys_sendto net/socket.c:2259 [inline]
__se_sys_sendto net/socket.c:2255 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2255
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fad3f879407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe6ec49960 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fad3f729c80 RCX: 00007fad3f879407
RDX: 0000000000000050 RSI: 00007ffe6ec49aa0 RDI: 0000000000000003
RBP: 00007ffe6ec49ed0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffe6ec49ee8
R13: 00007ffe6ec49aa0 R14: 0000000000000035 R15: 00007ffe6ec49aa0