INFO: task syz.3.10627:5350 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.3.10627 state:D stack:25320 pid:5350 tgid:5349 ppid:1978 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
cgroup_lock_and_drain_offline+0x51a/0x650 kernel/cgroup/cgroup.c:3275
cgroup_kn_lock_live+0x120/0x230 kernel/cgroup/cgroup.c:1715
cgroup_subtree_control_write+0x4b5/0x1080 kernel/cgroup/cgroup.c:3577
cgroup_file_write+0x331/0x8f0 kernel/cgroup/cgroup.c:4337
kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x612/0xba0 fs/read_write.c:687
ksys_write+0x150/0x270 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: 0033:0x7f14f939e0d9
RSP: 002b:00007f14fa339028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f14f9625fa0 RCX: 00007f14f939e0d9
RDX: 0000000000000005 RSI: 0000200000000300 RDI: 0000000000000006
RBP: 00007f14f9435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f14f9626038 R14: 00007f14f9625fa0 R15: 00007f14f974fa48
INFO: task syz.2.10652:5418 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.2.10652 state:D stack:26728 pid:5418 tgid:5411 ppid:570 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
cgroup_lock_and_drain_offline+0x51a/0x650 kernel/cgroup/cgroup.c:3275
cgroup_kn_lock_live+0x120/0x230 kernel/cgroup/cgroup.c:1715
cgroup_subtree_control_write+0x4b5/0x1080 kernel/cgroup/cgroup.c:3577
cgroup_file_write+0x331/0x8f0 kernel/cgroup/cgroup.c:4337
kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x612/0xba0 fs/read_write.c:687
ksys_write+0x150/0x270 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: 0033:0x7f52a639e0d9
RSP: 002b:00007f52a45b4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f52a6626180 RCX: 00007f52a639e0d9
RDX: 0000000000000005 RSI: 0000200000000300 RDI: 000000000000000a
RBP: 00007f52a6435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52a6626218 R14: 00007f52a6626180 R15: 00007f52a674fa48
INFO: task syz.2.10652:5424 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.2.10652 state:D stack:28808 pid:5424 tgid:5411 ppid:570 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
fdget_pos+0x246/0x320 fs/file.c:1259
class_fd_pos_constructor include/linux/file.h:85 [inline]
ksys_write+0x79/0x270 fs/read_write.c:730
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: 0033:0x7f52a639e0d9
RSP: 002b:00007f52a4191028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f52a6626270 RCX: 00007f52a639e0d9
RDX: 000000000000000b RSI: 0000200000000180 RDI: 000000000000000a
RBP: 00007f52a6435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52a6626308 R14: 00007f52a6626270 R15: 00007f52a674fa48
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5384:
#0: ffff8880328180a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5613:
5 locks held by kworker/u8:19/3689:
3 locks held by syz.3.10627/5350:
#0: ffff88804c958b70 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff888035e90450 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#1: ffff888035e90450 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffff888058308c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
3 locks held by syz.2.10652/5418:
#0: ffff88805a7ab7b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff888035e90450 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
#1: ffff888035e90450 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffff888075179880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
1 lock held by syz.2.10652/5424:
#0: ffff88805a7ab7b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
=============================================
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 07/24/2026
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 9c 7e 02 e9 93 06 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 2e 18 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e40 EFLAGS: 00000246
RAX: 0000000001ef8ec9 RBX: ffffffff819b5450 RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8e22f141 RDI: ffffffff8c4bdd80
RBP: ffffc90000197f10 R08: ffff8880b87338db R09: 1ffff110170e671b
R10: dffffc0000000000 R11: ffffed10170e671c R12: 0000000000000000
R13: 1ffff11003c54000 R14: 1ffff92000032fd0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff88812504b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff149f32159 CR3: 0000000074e32000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/kernel/process.c:767 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:768
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x2e0/0x540 kernel/sched/idle.c:355
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x157