INFO: task syz.2.635:8896 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.2.635 state:D stack:29064 pid:8896 tgid:8892 ppid:5830 task_flags:0x400040 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
tracing_splice_read_pipe+0x180/0xdd0 kernel/trace/trace.c:6895
do_splice_read fs/splice.c:982 [inline]
do_splice_read+0x285/0x370 fs/splice.c:956
splice_file_to_pipe+0x109/0x120 fs/splice.c:1292
do_sendfile+0x400/0xe50 fs/read_write.c:1376
__do_sys_sendfile64 fs/read_write.c:1431 [inline]
__se_sys_sendfile64 fs/read_write.c:1417 [inline]
__x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1417
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f736e38f7c9
RSP: 002b:00007f736c58b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f736e5e6270 RCX: 00007f736e38f7c9
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000001
RBP: 00007f736e413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000bff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f736e5e6308 R14: 00007f736e5e6270 R15: 00007ffd5491e558
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
1 lock held by syz-executor/5817:
#0: ffff888029359068 (&pipe->mutex){+.+.}-{4:4}, at: pipe_release+0x44/0x320 fs/pipe.c:729
2 locks held by syz.2.635/8894:
2 locks held by syz.2.635/8896:
#0: ffff888029359068 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock fs/pipe.c:91 [inline]
#0: ffff888029359068 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock+0x64/0x80 fs/pipe.c:88
#1: ffff88807bb20090 (&iter->mutex){+.+.}-{4:4}, at: tracing_splice_read_pipe+0x180/0xdd0 kernel/trace/trace.c:6895
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/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+0x133/0x180 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xe66/0x1180 kernel/hung_task.c:515
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8894 Comm: syz.2.635 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x70 kernel/kcov.c:217
Code: 00 00 5b e9 32 2c eb 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 65 48 8b 15 68 c9 f2 11 <65> 8b 05 79 c9 f2 11 a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00
RSP: 0018:ffffc90004f07b90 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81c0a743
RDX: ffff88802b609e80 RSI: ffffffff81c0a715 RDI: 0000000000000007
RBP: 0000000000000200 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88802b60a9b0 R12: 0000000000000000
R13: ffff88813ff68818 R14: 0000000000000000 R15: ffff88813ff688e0
FS: 00007f736c5cd6c0(0000) GS:ffff888124a0e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3722afde9c CR3: 000000007e25a000 CR4: 00000000003526f0
Call Trace:
<TASK>
ring_buffer_empty_cpu+0x205/0x3b0 kernel/trace/ring_buffer.c:6366
trace_empty+0x2d7/0x360 kernel/trace/trace.c:4395
tracing_wait_pipe+0x111/0x220 kernel/trace/trace.c:6664
tracing_read_pipe+0x366/0xcf0 kernel/trace/trace.c:6745
vfs_read+0x1e4/0xcf0 fs/read_write.c:570
ksys_read+0x12a/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f736e38f7c9
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:00007f736c5cd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f736e5e6090 RCX: 00007f736e38f7c9
RDX: 0000000000000036 RSI: 0000200000000280 RDI: 0000000000000003
RBP: 00007f736e413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f736e5e6128 R14: 00007f736e5e6090 R15: 00007ffd5491e558
</TASK>