INFO: task syz.2.6175:29473 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.6175 state:D stack:26760 pid:29473 tgid:29470 ppid:27663 task_flags:0x400448 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/io_uring.c:3327
io_uring_files_cancel include/linux/io_uring.h:19 [inline]
do_exit+0x345/0x2300 kernel/exit.c:912
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9211f8f6c9
RSP: 002b:00007f9212e25038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 00007f92121e5fa0 RCX: 00007f9211f8f6c9
RDX: 0000000000001001 RSI: 00002000000019c0 RDI: 0000000000000008
RBP: 00007f9212011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f92121e6038 R14: 00007f92121e5fa0 R15: 00007f921230fa28
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:3/49:
#0: ffff88801a069148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88801a069148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffff8880b8824048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
2 locks held by getty/5590:
#0: ffff88814cf7f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by kworker/0:1/16902:
1 lock held by syz.2.6175/29473:
#0: ffff8881423e00a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
6 locks held by syz.2.6175/29518:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 29518 Comm: syz.2.6175 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4790 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4875 [inline]
RIP: 0010:__lock_acquire+0x5a6/0xd20 kernel/locking/lockdep.c:5187
Code: c6 00 00 00 02 0f 84 51 ff ff ff 89 d0 e9 4a ff ff ff 48 c7 c7 b0 e1 e0 8d 48 89 de e8 23 88 24 03 48 8b 3c 24 e9 56 ff ff ff <83> bf 14 0b 00 00 00 41 0f 94 c4 45 00 e4 41 80 c4 03 44 3b bf 28
RSP: 0018:ffffc90003ed65e8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000ffffffff
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88802fd70000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81738c45
R10: ffffc90003ed6838 R11: ffffffff81ac2ea0 R12: ffffffffffffffff
R13: 0000000000000001 R14: ffff88802fd70b80 R15: 0000000000000000
FS: 00007f9212d9f6c0(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005638fa29e168 CR3: 0000000027486000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:332
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
prep_new_page mm/page_alloc.c:1858 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3884
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
__alloc_pages_noprof mm/page_alloc.c:5217 [inline]
alloc_pages_bulk_noprof+0x560/0x710 mm/page_alloc.c:5137
___alloc_pages_bulk mm/kasan/shadow.c:345 [inline]
__kasan_populate_vmalloc mm/kasan/shadow.c:370 [inline]
kasan_populate_vmalloc+0xd1/0x270 mm/kasan/shadow.c:435
alloc_vmap_area+0xd7a/0x14c0 mm/vmalloc.c:2098
__get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3193
__vmalloc_node_range_noprof+0x30c/0x12d0 mm/vmalloc.c:3857
vmalloc_user_noprof+0xad/0xf0 mm/vmalloc.c:4050
vb2_vmalloc_alloc+0xef/0x340 drivers/media/common/videobuf2/videobuf2-vmalloc.c:47
__vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:242 [inline]
__vb2_queue_alloc+0x9c2/0x15a0 drivers/media/common/videobuf2/videobuf2-core.c:523
vb2_core_reqbufs+0xc31/0x1420 drivers/media/common/videobuf2/videobuf2-core.c:964
__vb2_init_fileio+0x318/0xff0 drivers/media/common/videobuf2/videobuf2-core.c:2895
vb2_core_poll+0x4c1/0x840 drivers/media/common/videobuf2/videobuf2-core.c:2729
vb2_poll drivers/media/common/videobuf2/videobuf2-v4l2.c:979 [inline]
vb2_fop_poll+0x193/0x310 drivers/media/common/videobuf2/videobuf2-v4l2.c:1245
v4l2_poll+0x147/0x2c0 drivers/media/v4l2-core/v4l2-dev.c:350
vfs_poll include/linux/poll.h:82 [inline]
__io_arm_poll_handler+0x372/0xbb0 io_uring/poll.c:579
io_arm_apoll+0x597/0x910 io_uring/poll.c:687
io_queue_async+0x175/0x240 io_uring/io_uring.c:2055
io_queue_sqe io_uring/io_uring.c:2081 [inline]
io_submit_sqe io_uring/io_uring.c:2334 [inline]
io_submit_sqes+0xe78/0x1e60 io_uring/io_uring.c:2447
__do_sys_io_uring_enter io_uring/io_uring.c:3514 [inline]
__se_sys_io_uring_enter+0x2df/0x2b20 io_uring/io_uring.c:3453
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9211f8f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9212d9f038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f92121e6090 RCX: 00007f9211f8f6c9
RDX: 0000000000000000 RSI: 00000000000047ba RDI: 0000000000000007
RBP: 00007f9212011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000028 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f92121e6128 R14: 00007f92121e6090 R15: 00007f921230fa28