INFO: task kworker/1:0:22 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0 state:D stack:24144 pid:22 ppid:2 flags:0x00004000
Workqueue: events __set_printk_clr_event
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
__ftrace_set_clr_event kernel/trace/trace_events.c:1219 [inline]
trace_set_clr_event+0xbe/0x130 kernel/trace/trace_events.c:1285
__set_printk_clr_event+0x1e/0x70 kernel/trace/bpf_trace.c:416
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
INFO: task syz.4.452:5807 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.452 state:D stack:26512 pid:5807 ppid:4284 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
subsystem_open+0x44/0x380 kernel/trace/trace_events.c:1903
do_dentry_open+0x7dd/0x10b0 fs/open.c:882
do_open fs/namei.c:3677 [inline]
path_openat+0x2674/0x2f10 fs/namei.c:3834
do_filp_open+0x1ee/0x420 fs/namei.c:3861
do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
do_sys_open fs/open.c:1336 [inline]
__do_sys_openat fs/open.c:1352 [inline]
__se_sys_openat fs/open.c:1347 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1347
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe72e79e159
RSP: 002b:00007fe72f597028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fe72ea26090 RCX: 00007fe72e79e159
RDX: 0000000000000001 RSI: 0000200000000300 RDI: ffffffffffffff9c
RBP: 00007fe72e83503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe72ea26128 R14: 00007fe72ea26090 R15: 00007fff63cbb5c8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2e5b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2edd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
3 locks held by kworker/1:0/22:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc900001c7d00 (set_printk_work){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffffffff8cb82ee8 (event_mutex){+.+.}-{3:3}, at: __ftrace_set_clr_event kernel/trace/trace_events.c:1219 [inline]
#2: ffffffff8cb82ee8 (event_mutex){+.+.}-{3:3}, at: trace_set_clr_event+0xbe/0x130 kernel/trace/trace_events.c:1285
1 lock held by khungtaskd/28:
#0: ffffffff8cb2dc20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2dc20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2dc20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527
2 locks held by getty/4025:
#0: ffff88814d779098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198
3 locks held by kworker/u5:1/4275:
#0: ffff88807606b938 ((wq_completion)hci8){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc900041e7d00 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffff888053e951e0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open net/bluetooth/hci_core.c:450 [inline]
#2: ffff888053e951e0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_power_on+0x19f/0x6b0 net/bluetooth/hci_core.c:953
7 locks held by syz.0.372/5586:
1 lock held by syz.4.452/5807:
#0: ffffffff8cb82ee8 (event_mutex){+.+.}-{3:3}, at: subsystem_open+0x44/0x380 kernel/trace/trace_events.c:1903
1 lock held by syz.1.555/6111:
#0: ffffffff8cb82ee8 (event_mutex){+.+.}-{3:3}, at: subsystem_open+0x44/0x380 kernel/trace/trace_events.c:1903
2 locks held by syz.6.1111/8053:
#0: ffff88802846d098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#0: ffff88802846d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:336 [inline]
#0: ffff88802846d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#0: ffff88802846d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x58/0x200 drivers/tty/tty_ldisc.c:781
#1: ffff8880550ad098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:296 [inline]
#1: ffff8880550ad098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:338 [inline]
#1: ffff8880550ad098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#1: ffff8880550ad098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0x7c/0x200 drivers/tty/tty_ldisc.c:781
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf0e/0xf50 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5586 Comm: syz.0.372 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:178 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:241 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x13/0x80 kernel/kcov.c:309
Code: 11 08 03 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 90 48 8b 04 24 65 48 8b 15 44 2a 80 7e 65 8b 0d 45 2a 80 7e <81> e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 1c 16 00 00
RSP: 0018:ffffc900039d6c38 EFLAGS: 00000246
RAX: ffffffff8a2480cd RBX: dffffc0000000000 RCX: 0000000080000000
RDX: ffff8880539dbc00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffff8880539dbc00 R09: 0000000000000002
R10: 0000000000000406 R11: 0000000000000002 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000007
FS: 00007f4ff39cb6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555913a0a38 CR3: 000000002212d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:820 [inline]
xa_load+0x22d/0x2e0 lib/xarray.c:1467
list_lru_from_memcg_idx mm/list_lru.c:56 [inline]
list_lru_count_one+0x135/0x2c0 mm/list_lru.c:185
list_lru_shrink_count include/linux/list_lru.h:122 [inline]
nfs4_xattr_entry_count+0x76/0x120 fs/nfs/nfs42xattr.c:977
do_shrink_slab+0x85/0xdb0 mm/vmscan.c:800
shrink_slab_memcg mm/vmscan.c:922 [inline]
shrink_slab+0x448/0x740 mm/vmscan.c:1001
shrink_node_memcgs mm/vmscan.c:6154 [inline]
shrink_node+0x6e5/0x2890 mm/vmscan.c:6183
shrink_zones mm/vmscan.c:6424 [inline]
do_try_to_free_pages+0x650/0x1980 mm/vmscan.c:6486
try_to_free_mem_cgroup_pages+0x335/0x8c0 mm/vmscan.c:6801
try_charge_memcg+0x5da/0x17c0 mm/memcontrol.c:2684
obj_cgroup_charge_pages mm/memcontrol.c:3099 [inline]
obj_cgroup_charge+0x36a/0x620 mm/memcontrol.c:3390
memcg_slab_pre_alloc_hook mm/slab.h:501 [inline]
slab_pre_alloc_hook+0x2e2/0x300 mm/slab.h:715
slab_alloc_node mm/slub.c:3279 [inline]
slab_alloc mm/slub.c:3367 [inline]
__kmem_cache_alloc_lru mm/slub.c:3374 [inline]
kmem_cache_alloc_lru+0x49/0x2e0 mm/slub.c:3390
__d_alloc+0x2e/0x6e0 fs/dcache.c:1774
d_alloc fs/dcache.c:1854 [inline]
d_alloc_parallel+0xdc/0x1590 fs/dcache.c:2647
__lookup_slow+0x134/0x3f0 fs/namei.c:1683
lookup_one_len+0x19d/0x2d0 fs/namei.c:2791
start_creating+0x113/0x200 fs/tracefs/inode.c:426
__create_dir+0x24/0x530 fs/tracefs/inode.c:515
event_subsystem_dir kernel/trace/trace_events.c:2488 [inline]
event_create_dir+0x4bd/0xe50 kernel/trace/trace_events.c:2582
__trace_add_new_event kernel/trace/trace_events.c:2988 [inline]
__trace_add_event_dirs kernel/trace/trace_events.c:3202 [inline]
event_trace_add_tracer+0x19b/0x3a0 kernel/trace/trace_events.c:3801
trace_array_create_dir+0x77/0x120 kernel/trace/trace.c:9431
trace_array_create+0x724/0xcb0 kernel/trace/trace.c:9489
instance_mkdir+0xc8/0x120 kernel/trace/trace.c:9524
tracefs_syscall_mkdir+0xb7/0x110 fs/tracefs/inode.c:87
vfs_mkdir+0x386/0x570 fs/namei.c:4157
do_mkdirat+0x1d8/0x440 fs/namei.c:4182
__do_sys_mkdirat fs/namei.c:4197 [inline]
__se_sys_mkdirat fs/namei.c:4195 [inline]
__x64_sys_mkdirat+0x85/0x90 fs/namei.c:4195
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4ff2b9e159
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:00007f4ff39cb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f4ff2e25fa0 RCX: 00007f4ff2b9e159
RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007f4ff2c3503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4ff2e26038 R14: 00007f4ff2e25fa0 R15: 00007ffe56a590f8