INFO: task syz.3.1528:22790 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1528 state:D stack:26008 pid:22790 tgid:22786 ppid:22098 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251
__super_lock fs/super.c:58 [inline]
super_lock+0x289/0x3d0 fs/super.c:122
user_get_super+0xc8/0x120 fs/super.c:941
quotactl_block fs/quota/quota.c:889 [inline]
__do_sys_quotactl fs/quota/quota.c:955 [inline]
__se_sys_quotactl+0x538/0x9a0 fs/quota/quota.c:917
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: 0033:0x7fe33155ce59
RSP: 002b:00007fe32f7ae028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fe3317d5fa0 RCX: 00007fe33155ce59
RDX: 0000000000000000 RSI: 0000200000000080 RDI: ffffffff80000200
RBP: 00007fe3315f2e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe3317d6038 R14: 00007fe3317d5fa0 R15: 00007ffe1c51e2e8
INFO: task syz.6.1540:22914 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1540 state:D stack:26008 pid:22914 tgid:22913 ppid:22289 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1502 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1576
__super_lock fs/super.c:60 [inline]
super_lock+0x2d6/0x3d0 fs/super.c:122
user_get_super+0xc8/0x120 fs/super.c:941
quotactl_block fs/quota/quota.c:889 [inline]
__do_sys_quotactl fs/quota/quota.c:955 [inline]
__se_sys_quotactl+0x538/0x9a0 fs/quota/quota.c:917
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: 0033:0x7fd23da6ce59
RSP: 002b:00007fd23bcc6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fd23dce5fa0 RCX: 00007fd23da6ce59
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffff80000800
RBP: 00007fd23db02e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000100 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd23dce6038 R14: 00007fd23dce5fa0 R15: 00007ffd441eb898
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:preempt_latency_start kernel/sched/core.c:5956 [inline]
RIP: 0010:preempt_count_add+0x74/0x190 kernel/sched/core.c:5982
Code: c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e5 00 00 00 83 3d 8f 14 e8 17 00 75 11 65 8b 05 36 cf dc 10 0f b6 c0 3d f5 00 00 00 73 5d <65> 8b 05 25 cf dc 10 25 ff ff ff 7f 39 f8 75 42 48 8b 5c 24 18 48
RSP: 0018:ffffc90000167a08 EFLAGS: 00000297
RAX: 0000000000000001 RBX: 0000000000000899 RCX: ffffffff997b7503
RDX: 00000000000001b0 RSI: ffffffff8ba92960 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8b2418c0 R12: 1ffffffff336dd96
R13: 00000000ffffffff R14: 000001b09027c2e6 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff88812611d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd87652b90 CR3: 0000000082980000 CR4: 00000000003526f0
Call Trace:
delay_tsc+0x65/0xc0 arch/x86/lib/delay.c:79
udelay include/asm-generic/delay.h:62 [inline]
wait_for_lsr+0x14d/0x300 drivers/tty/serial/8250/8250_port.c:1988
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3229 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3312 [inline]
serial8250_console_write+0x12a2/0x1b40 drivers/tty/serial/8250/8250_port.c:3379
console_emit_next_record kernel/printk/printk.c:3163 [inline]
console_flush_one_record+0x642/0xb50 kernel/printk/printk.c:3269
legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712
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