INFO: task syz.0.6749:21629 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.6749 state:D stack:27944 pid:21629 tgid:21626 ppid:5599 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7276
__schedule_loop kernel/sched/core.c:7353 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7368
cgroup_lock_and_drain_offline+0x383/0x800 kernel/cgroup/cgroup.c:3350
cgroup_kn_lock_live+0x188/0x520 kernel/cgroup/cgroup.c:1717
cgroup_subtree_control_write+0x3dd/0xe90 kernel/cgroup/cgroup.c:3652
cgroup_file_write+0x1e6/0x8a0 kernel/cgroup/cgroup.c:4412
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6af/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3e4739e159
RSP: 002b:00007f3e481c9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3e47625fa0 RCX: 00007f3e4739e159
RDX: 0000000000000005 RSI: 0000200000000040 RDI: 0000000000000005
RBP: 00007f3e4743503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3e47626038 R14: 00007f3e47625fa0 R15: 00007ffd34d7d048
Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by getty/5364: 1, last CPU#0:
#0: ffff8880375940a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
locks held by udevd/5906: 1, on CPU#0:
#0: ffff888027a63350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:990
locks held by udevd/6218: 1, last CPU#0:
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
locks held by syz.3.2148/10655: 1, last CPU#0:
#0: ffff88807d17bed0 (&ima_iint_mutex_key[depth]#2){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
locks held by syz-executor/11473: 4, last CPU#0:
#0: ffffffff8ef3d6f0 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff8ef3d6f0 (dup_mmap_sem){++++}-{0:0}, at: copy_mm kernel/fork.c:1595 [inline]
#0: ffffffff8ef3d6f0 (dup_mmap_sem){++++}-{0:0}, at: copy_process+0x4806/0x8370 kernel/fork.c:2307
#1: ffff888026164378 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#1: ffff888026164378 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x127/0x2370 mm/mmap.c:1716
#2: ffff888075534378 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
#2: ffff888075534378 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x1c9/0x2370 mm/mmap.c:1723
#3: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8edec2e0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by syz.0.6749/21629: 3, on CPU#0:
#0: ffff88803eb3a7f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88807d4f0460 (sb_writers#10){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffff88801fec2c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336
locks held by kworker/0:7/22169: 3, on CPU#0:
#0: ffff88801c05a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90003b67d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88802aacf1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802aacf1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4420 drivers/usb/core/hub.c:5912
locks held by syz.9.7698/24098: 1, last CPU#0:
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: __do_sys_io_uring_enter+0xa7e/0x1b10 io_uring/io_uring.c:2636
locks held by iou-wrk-24098/24103: 1, on CPU#0:
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:410 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_file_get_fixed io_uring/io_uring.c:1569 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_assign_file io_uring/io_uring.c:1359 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_assign_file io_uring/io_uring.c:1352 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_wq_submit_work+0x667/0xf70 io_uring/io_uring.c:1486
locks held by iou-wrk-24098/24107: 1, on CPU#0:
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:410 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_file_get_fixed io_uring/io_uring.c:1569 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_assign_file io_uring/io_uring.c:1359 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_assign_file io_uring/io_uring.c:1352 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_wq_submit_work+0x667/0xf70 io_uring/io_uring.c:1486
locks held by iou-wrk-24098/24109: 1, on CPU#0:
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_ring_submit_lock io_uring/io_uring.h:410 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_file_get_fixed io_uring/io_uring.c:1569 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_assign_file io_uring/io_uring.c:1359 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_assign_file io_uring/io_uring.c:1352 [inline]
#0: ffff8880542700a0 (&ctx->uring_lock){+.+.}-{4:4}, at: io_wq_submit_work+0x667/0xf70 io_uring/io_uring.c:1486
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245