INFO: task syz.9.2643:19205 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2643 state:D stack:28616 pid:19205 tgid:19197 ppid:17521 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
cgroup_lock_and_drain_offline+0x51a/0x650 kernel/cgroup/cgroup.c:3275
cgroup_kn_lock_live+0x120/0x230 kernel/cgroup/cgroup.c:1715
cgroup_subtree_control_write+0x4b5/0x1080 kernel/cgroup/cgroup.c:3577
cgroup_file_write+0x331/0x8f0 kernel/cgroup/cgroup.c:4316
kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x612/0xba0 fs/read_write.c:687
ksys_write+0x150/0x270 fs/read_write.c:739
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: 0033:0x7f532439de99
RSP: 002b:00007f53252fe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5324626180 RCX: 00007f532439de99
RDX: 0000000000000005 RSI: 0000200000000040 RDI: 000000000000000b
RBP: 00007f5324433eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5324626218 R14: 00007f5324626180 R15: 00007ffec602aca8
Showing all locks held in the system:
1 lock held by khungtaskd/32:
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5378:
#0: ffff888032a2d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
3 locks held by syz.9.2643/19205:
#0: ffff888026949cf0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff888033fd4450 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#1: ffff888033fd4450 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffff888051ed3c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
1 lock held by syz-executor/20036:
#0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5610 Comm: kworker/1:3 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events drain_vmap_area_work
RIP: 0010:unwind_next_frame+0x15e/0x2550 arch/x86/kernel/unwind_orc.c:510
Code: b6 04 20 84 c0 0f 85 9b 1c 00 00 f6 03 03 0f 85 fa 19 00 00 49 8d 5e 35 48 89 d8 48 c1 e8 03 48 89 04 24 42 0f b6 04 20 84 c0 <0f> 85 92 1c 00 00 4c 89 7c 24 10 4c 89 6c 24 50 0f b6 1b 48 8b 44
RSP: 0018:ffffc900030273e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900030274bd RCX: 0000000080000001
RDX: 0000000021cb7edb RSI: ffffffff8c4bdd60 RDI: ffffffff8c4bdd20
RBP: 1ffff92000604e98 R08: ffffffff8177827f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000
R13: ffffffff8177827f R14: ffffc90003027488 R15: 1ffff92000604e91
FS: 0000000000000000(0000) GS:ffff88812504e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558760dbbee8 CR3: 000000000e946000 CR4: 0000000000350ef0
Call Trace:
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950
kasan_depopulate_vmalloc_pte+0x6d/0x90 mm/kasan/shadow.c:484
apply_to_pte_range mm/memory.c:3338 [inline]
apply_to_pmd_range mm/memory.c:3382 [inline]
apply_to_pud_range mm/memory.c:3418 [inline]
apply_to_p4d_range mm/memory.c:3454 [inline]
__apply_to_page_range+0xbd8/0x1420 mm/memory.c:3490
__kasan_release_vmalloc+0xa2/0xd0 mm/kasan/shadow.c:602
kasan_release_vmalloc include/linux/kasan.h:593 [inline]
kasan_release_vmalloc_node mm/vmalloc.c:2284 [inline]
purge_vmap_node+0x220/0x960 mm/vmalloc.c:2306
__purge_vmap_area_lazy+0x783/0xb40 mm/vmalloc.c:2396
drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2430
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
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