INFO: task syz.3.1620:12228 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1620 state:D stack:27496 pid:12228 tgid:12227 ppid:5598 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607
rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline]
rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578
bdev_open+0xde/0xd00 block/bdev.c:948
blkdev_open+0x47f/0x630 block/fops.c:672
do_dentry_open+0x849/0x1420 fs/open.c:947
vfs_open+0x3b/0x350 fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x2e60/0x3850 fs/namei.c:4863
do_file_open+0x23e/0x4a0 fs/namei.c:4892
do_sys_openat2+0x115/0x200 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1385
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: 0033:0x7f2a5e52e6ce
RSP: 002b:00007f2a5c7c5b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2a5c7c66c0 RCX: 00007f2a5e52e6ce
RDX: 0000000000008000 RSI: 00007f2a5c7c5c00 RDI: ffffffffffffff9c
RBP: 00007f2a5c7c5c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f2a5e7f6038 R14: 00007f2a5e7f5fa0 R15: 00007ffedd751728
Showing all locks held in the system:
3 locks held by kworker/0:0H/11:
#0: ffff88813ff1f538 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88813ff1f538 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc90000107c40 ((w[ 840.122066][ T37] #1: ffffc90000107c40 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc90000107c40 ((w[ 840.122066][ T37] #1: ffffc90000107c40 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8f50d418 (clients_lock#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8f50d418 (clients_lock#2){+.+.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:620 [inline]
#2: ffffffff8f50d418 (clients_lock#2){+.+.}-{3:3}, at: client_use_ptr+0x4d/0xa90 sound/core/seq/seq_clientmgr.c:118
1 lock held by khungtaskd/37:
#0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5348:
#0: ffff8880360fb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:4/5605:
2 locks held by kworker/u8:12/6317:
#0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc900063a7c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc900063a7c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
1 lock held by udevd/10215:
#0: ffff888026e4a4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:948
1 lock held by udevd/10322:
#0: ffff88802744a4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:948
1 lock held by udevd/10323:
#0: ffff888026de34c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:948
1 lock held by udevd/10353:
#0: ffff888026e634c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:948
1 lock held by udevd/11479:
#0: ffff8880272a24c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:948
1 lock held by syz.3.1620/12228:
#0: ffff888026e634c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:948
2 locks held by syz-executor/12389:
5 locks held by kworker/u8:34/12790:
1 lock held by syz.0.2105/14166:
3 locks held by syz.2.2123/14231:
1 lock held by syz.2.2167/14326:
1 lock held by syz.0.2171/14332:
5 locks held by syz.7.2174/14331:
8 locks held by syz.8.2173/14334:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14334 Comm: syz.8.2173 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:__lock_release kernel/locking/lockdep.c:5518 [inline]
RIP: 0010:lock_release+0xb7/0x3c0 kernel/locking/lockdep.c:5889
Code: 84 ea 01 00 00 9c 5b fa 48 c7 c7 4c e6 89 8d e8 ef 0a a2 09 65 ff 05 90 9d fc 10 c7 44 24 24 01 00 00 00 83 3d 19 1d 0e 0e 00 <0f> 84 90 01 00 00 41 8b 87 00 0c 00 00 85 c0 0f 84 17 01 00 00 4c
RSP: 0018:ffffc900108df858 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000004 RSI: ffffffff8d89e64c RDI: ffffffff8bca7780
RBP: dffffc0000000000 R08: ffffffff8233dec5 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8e1c3000 R12: ffffffff82336b40
R13: ffffffff82336b40 R14: ffffffff8e1c3000 R15: ffff8880203d9f00
FS: 00007fc685f766c0(0000) GS:ffff888125c42000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc685f54ff8 CR3: 0000000060e4c000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
get_obj_cgroup_from_memcg mm/memcontrol.c:2930 [inline]
charge_memcg+0xeb/0x2b0 mm/memcontrol.c:5123
__mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:5143
mem_cgroup_charge include/linux/memcontrol.h:641 [inline]
shmem_alloc_and_add_folio mm/shmem.c:1959 [inline]
shmem_get_folio_gfp+0x81a/0x1c40 mm/shmem.c:2502
shmem_get_folio mm/shmem.c:2608 [inline]
shmem_write_begin+0x166/0x320 mm/shmem.c:3239
generic_perform_write+0x2ad/0x8b0 mm/filemap.c:4358
shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3414
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61e/0xbb0 fs/read_write.c:687
ksys_write+0x156/0x270 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: 0033:0x7fc687d1de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc685f76028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc687fa5fa0 RCX: 00007fc687d1de99
RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007fc687db3eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc687fa6038 R14: 00007fc687fa5fa0 R15: 00007ffeb70726a8