INFO: task syz.0.18:6439 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.18 state:D stack:27896 pid:6439 tgid:6438 ppid:6321 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1539/0x5080 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153
__flush_work+0xa17/0xc50 kernel/workqueue.c:4331
__cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4451
p9_conn_destroy net/9p/trans_fd.c:806 [inline]
p9_fd_close+0x251/0x430 net/9p/trans_fd.c:841
p9_client_create+0x68d/0xc90 net/9p/client.c:937
v9fs_session_init+0x46/0xdf0 fs/9p/v9fs.c:442
v9fs_get_tree+0xbd/0xac0 fs/9p/vfs_super.c:97
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3760 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3836
do_mount fs/namespace.c:4159 [inline]
__do_sys_mount fs/namespace.c:4348 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4325
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9eb099a679
RSP: 002b:00007f9eb1788028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9eb0c05fa0 RCX: 00007f9eb099a679
RDX: 0000200000000540 RSI: 0000200000000180 RDI: 0000000000000000
RBP: 00007f9eb0a2dee0 R08: 0000200000000580 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9eb0c06038 R14: 00007f9eb0c05fa0 R15: 00007ffd3b0806e8
Showing all locks held in the system:
2 locks held by kworker/0:0/9:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc900000e7c40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
2 locks held by kworker/1:0/24:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc900001e7c40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
1 lock held by khungtaskd/30:
#0: ffffffff8e75dda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75dda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75dda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:3/49:
2 locks held by kworker/0:2/860:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc90003597c40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
2 locks held by kworker/1:2/948:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc90003a7fc40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
2 locks held by kworker/0:3/982:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc90003b1fc40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
2 locks held by getty/5583:
#0: ffff8880338060a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by kworker/1:4/5925:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc900035f7c40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
2 locks held by kworker/1:5/5987:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc90003617c40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
2 locks held by kworker/1:6/6496:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc90003e07c40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
2 locks held by kworker/0:7/6523:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc90003f47c40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
3 locks held by kworker/1:9/6635:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc90004547c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
#2: ffff888033bfb240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0 drivers/net/netdevsim/fib.c:1490
2 locks held by kworker/1:10/6654:
#0: ffff88813ff0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc90004627c40 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
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:161 [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:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 145 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:user_mode arch/x86/include/asm/ptrace.h:214 [inline]
RIP: 0010:unwind_next_frame+0x141/0x23c0 arch/x86/kernel/unwind_orc.c:498
Code: 4c 89 e8 48 c1 e8 03 48 89 44 24 38 80 3c 28 00 74 08 4c 89 ef e8 0f d9 b7 00 49 8b 5d 00 48 85 db 74 23 48 81 c3 88 00 00 00 <48> 89 d8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 4e 1b 00 00 f6 03 03
RSP: 0018:ffffc90000a08898 EFLAGS: 00000292
RAX: 1ffff92000141137 RBX: ffffc90002ef7740 RCX: 0000000000000102
RDX: 00000000e8a11906 RSI: ffffffff8c2755e0 RDI: ffffffff8c2755a0
RBP: dffffc0000000000 R08: ffffffff81761295 R09: ffffffff8e75dda0
R10: ffffc90000a089b8 R11: ffffffff81afeb50 R12: 1ffff9200014112d
R13: ffffc90000a089b8 R14: ffffc90000a08968 R15: ffffffff81761295
FS: 0000000000000000(0000) GS:ffff8881253be000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f162c3cdff8 CR3: 000000000e54a000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2621 [inline]
__rcu_free_sheaf_prepare+0x129/0x290 mm/slub.c:2851
rcu_free_sheaf+0x31/0x200 mm/slub.c:5675
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
handle_softirqs+0x22a/0x7c0 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:727
irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xce5/0x1270 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 84 dc 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 2f d8 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 13 d8
RSP: 0018:ffffc90002ef7760 EFLAGS: 00000293
RAX: ffffffff81b8d1fd RBX: 1ffff110170884d5 RCX: ffff888020b45ac0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002ef78a0 R08: ffffffff901007b7 R09: 1ffffffff20200f6
R10: dffffc0000000000 R11: fffffbfff20200f7 R12: ffff8880b84426a8
R13: dffffc0000000000 R14: ffff8880b853bd80 R15: 0000000000000000
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2746 [inline]
smp_text_poke_batch_finish+0xb5f/0x1160 arch/x86/kernel/alternative.c:3018
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:884
process_one_work+0x949/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0xb46/0x1140 kernel/workqueue.c:3443
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245