INFO: task syz.4.11643:12188 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.11643 state:D stack:22728 pid:12188 tgid:12188 ppid:6988 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5030 kernel/sched/core.c:6864
__schedule_loop kernel/sched/core.c:6946 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6961
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018
__mutex_lock_common kernel/locking/mutex.c:686 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:770
ima_check_last_writer security/integrity/ima/ima_main.c:192 [inline]
ima_file_free+0x16c/0x460 security/integrity/ima/ima_main.c:233
security_file_release+0x93/0x150 security/security.c:2398
__fput+0x3b3/0xa70 fs/file_table.c:462
task_work_run+0x1d4/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcdfb58f749
RSP: 002b:00007ffcd0096068 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fcdfb7e7da0 RCX: 00007fcdfb58f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fcdfb7e7da0 R08: 0000000000027eb4 R09: 00000019d009635f
R10: 00007fcdfb7e7cb0 R11: 0000000000000246 R12: 000000000034330d
R13: 00007ffcd0096160 R14: ffffffffffffffff R15: 00007ffcd0096180
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df3d980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5594:
#0: ffff8880354830a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/1:2/15088:
#0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236
#1: ffffc9000471fb80 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237
1 lock held by syz.4.11643/12188:
#0: ffff8880559ea6c8 (&ima_iint_mutex_key[depth]#2){+.+.}-{4:4}, at: ima_check_last_writer security/integrity/ima/ima_main.c:192 [inline]
#0: ffff8880559ea6c8 (&ima_iint_mutex_key[depth]#2){+.+.}-{4:4}, at: ima_file_free+0x16c/0x460 security/integrity/ima/ima_main.c:233
2 locks held by syz.4.11643/12193:
3 locks held by syz.6.11901/13188:
1 lock held by syz.2.11911/13214:
#0: ffff8880559eaf48 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_check_last_writer security/integrity/ima/ima_main.c:192 [inline]
#0: ffff8880559eaf48 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_file_free+0x16c/0x460 security/integrity/ima/ima_main.c:233
1 lock held by syz.2.11911/13231:
2 locks held by syz.9.11913/13228:
1 lock held by syz.9.11917/13243:
2 locks held by syz.1.11918/13245:
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f2daf08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
#1: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8df43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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]
__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:346 [inline]
watchdog+0xfb5/0x1000 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13243 Comm: syz.9.11917 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:hrtimer_get_expires include/linux/hrtimer.h:135 [inline]
RIP: 0010:__hrtimer_next_event_base+0xeb/0x2d0 kernel/time/hrtimer.c:526
Code: 79 00 4d 8b 3f 4d 39 f7 74 07 e8 00 a9 12 00 eb 19 4c 89 ff e8 c6 70 a8 09 48 85 c0 0f 84 41 01 00 00 49 89 c7 e8 e5 a8 12 00 <4d> 8d 6f 18 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80
RSP: 0018:ffffc90000007e48 EFLAGS: 00000006
RAX: ffffffff81af3070 RBX: 0000000000000000 RCX: ffff888027d6bd00
RDX: 0000000000010000 RSI: 0000000000000004 RDI: 0000000000000009
RBP: ffff8880b86284c0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f84 R12: 7fffffffffffffff
R13: 0000000000000010 R14: 0000000000000000 R15: ffff888029f9f0b8
FS: 00007f20371946c0(0000) GS:ffff888125eba000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f51f1fb42f8 CR3: 000000007c5d6000 CR4: 00000000003526f0
Call Trace:
__hrtimer_get_next_event kernel/time/hrtimer.c:580 [inline]
hrtimer_update_next_event kernel/time/hrtimer.c:606 [inline]
hrtimer_interrupt+0x4e2/0xaa0 kernel/time/hrtimer.c:1906
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x410 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217
Code: 08 60 76 92 65 8b 15 a8 86 b4 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 6c 16 00 00 00 74 2c 8b 91 48 16 00 00 <83> fa 02 75 21 48 8b 91 50 16 00 00 48 8b 32 48 8d 7e 01 8b 89 4c
RSP: 0018:ffffc9000bfa74f0 EFLAGS: 00000246
RAX: ffffffff818cd972 RBX: 0000000000000000 RCX: ffff888027d6bd00
RDX: 0000000000000002 RSI: 000000000007ffff RDI: 0000000000000000
RBP: ffffc9000bfa75f0 R08: ffffc9000bfa779f R09: 0000000000000000
R10: ffffc9000bfa7780 R11: fffff520017f4ef4 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff920017f4ef0 R15: 0000000000000000
put_pid+0x12/0x130 kernel/pid.c:91
scm_destroy_cred include/net/scm.h:80 [inline]
scm_destroy include/net/scm.h:86 [inline]
__scm_recv_common+0x3a0/0x610 net/core/scm.c:505
scm_recv_unix+0xab/0x360 net/core/scm.c:541
__unix_dgram_recvmsg+0x9ec/0xd60 net/unix/af_unix.c:2655
sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1082
____sys_recvmsg+0x3aa/0x460 net/socket.c:2852
___sys_recvmsg+0x1b5/0x510 net/socket.c:2896
do_recvmmsg+0x307/0x770 net/socket.c:2991
__sys_recvmmsg net/socket.c:3065 [inline]
__do_sys_recvmmsg net/socket.c:3088 [inline]
__se_sys_recvmmsg net/socket.c:3081 [inline]
__x64_sys_recvmmsg+0x190/0x240 net/socket.c:3081
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: 0033:0x7f203638f749
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:00007f2037194038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f20365e5fa0 RCX: 00007f203638f749
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f2036413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f20365e6038 R14: 00007f20365e5fa0 R15: 00007ffcc78c19f8