INFO: task syz.5.12896:9505 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.5.12896 state:D stack:28832 pid:9505 tgid:9502 ppid:31834 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5310 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
rwsem_down_write_slowpath+0x899/0x1040 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1bc/0x200 kernel/locking/rwsem.c:1591
__super_lock fs/super.c:58 [inline]
super_lock+0x289/0x3d0 fs/super.c:122
user_get_super+0xc8/0x120 fs/super.c:1001
quotactl_block fs/quota/quota.c:889 [inline]
__do_sys_quotactl fs/quota/quota.c:955 [inline]
__se_sys_quotactl+0x540/0x9e0 fs/quota/quota.c:917
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc98dd9aeb9
RSP: 002b:00007fc98ec98028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fc98e015fa0 RCX: 00007fc98dd9aeb9
RDX: ffffffffffffffff RSI: 0000200000000180 RDI: ffffffff80000201
RBP: 00007fc98de08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc98e016038 R14: 00007fc98e015fa0 R15: 00007ffd0fc13bb8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e760320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e760320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e760320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/48:
4 locks held by dhcpcd/5484:
2 locks held by getty/5582:
#0: ffff888032f710a0 (&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by udevd/5974:
1 lock held by udevd/6995:
#0: ffff88802735c358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
2 locks held by syz-executor/7453:
6 locks held by kworker/u8:9/21342:
#0: ffff88801c2ae948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc9000e13fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8fbb8e50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670
#3: ffff88805f5490e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88805f5490e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff88805f5490e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x117/0x3f0 net/devlink/core.c:504
#4: ffff88805f54f250 (&devlink->lock_key#23){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:274 [inline]
#4: ffff88805f54f250 (&devlink->lock_key#23){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff88805f54f250 (&devlink->lock_key#23){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x3f0 net/devlink/core.c:504
#5: ffffffff8e766480 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz.5.12896/9505:
#0: ffff88807c22a0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807c22a0e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x289/0x3d0 fs/super.c:122
1 lock held by syz.8.13095/10182:
#0: ffff88807c22a0e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807c22a0e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz-executor/11126:
#0: ffffffff8e7665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e7665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
3 locks held by syz-executor/12477:
2 locks held by syz.6.13600/12566:
2 locks held by sed/12576:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:347 [inline]
watchdog+0x103d/0x1090 kernel/hung_task.c:516
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 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: 9447 Comm: kworker/u8:15 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: writeback wb_workfn (flush-7:4)
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: c7 86 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 8c b2 f0 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 c7 f2 71 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000b0965b0 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888141af8237 R09: 1ffff1102835f046
R10: dffffc0000000000 R11: ffffffff853ed5d0 R12: dffffc0000000000
R13: ffffffff9a2aca4f R14: ffffffff9a5c3b20 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812556a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93e8c6b7d0 CR3: 00000000a1980000 CR4: 00000000003526f0
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x140c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3131 [inline]
console_flush_one_record kernel/printk/printk.c:3217 [inline]
console_flush_all+0x718/0xb20 kernel/printk/printk.c:3291
__console_flush_and_unlock kernel/printk/printk.c:3321 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3361
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2428
_printk+0xdd/0x130 kernel/printk/printk.c:2453
bio_check_eod block/blk-core.c:566 [inline]
submit_bio_noacct+0x12b6/0x1c20 block/blk-core.c:806
__submit_merged_bio+0x256/0x700 fs/f2fs/data.c:581
__f2fs_submit_merged_write fs/f2fs/data.c:678 [inline]
__submit_merged_write_cond+0x3c3/0x4e0 fs/f2fs/data.c:702
f2fs_submit_merged_write_cond fs/f2fs/data.c:727 [inline]
f2fs_write_cache_pages fs/f2fs/data.c:3480 [inline]
__f2fs_write_data_pages fs/f2fs/data.c:3588 [inline]
f2fs_write_data_pages+0x2975/0x35e0 fs/f2fs/data.c:3626
do_writepages+0x32e/0x550 mm/page-writeback.c:2554
__writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750
writeback_sb_inodes+0x944/0x19a0 fs/fs-writeback.c:2041
wb_writeback+0x456/0xb70 fs/fs-writeback.c:2227
wb_do_writeback fs/fs-writeback.c:2374 [inline]
wb_workfn+0x414/0xf50 fs/fs-writeback.c:2414
process_one_work+0x949/0x1650 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0xb46/0x1140 kernel/workqueue.c:3443
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: c7 86 fc 44 89 f9 d3 movl $0x8349e5d3,-0x676bb04(%rsi)
7: e5 49 83
a: c6 40 4c 89 movb $0x89,0x4c(%rax)
e: f0 48 c1 e8 03 lock shr $0x3,%rax
13: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
18: 74 08 je 0x22
1a: 4c 89 f7 mov %r14,%rdi
1d: e8 8c b2 f0 fc call 0xfcf0b2ae
22: 41 03 2e add (%r14),%ebp
25: 89 d8 mov %ebx,%eax
27: 89 ea mov %ebp,%edx
29: ee out %al,(%dx)
* 2a: 5b pop %rbx <-- trapping instruction
2b: 41 5c pop %r12
2d: 41 5e pop %r14
2f: 41 5f pop %r15
31: 5d pop %rbp
32: e9 c7 f2 71 06 jmp 0x671f2fe
37: cc int3
38: 44 89 f9 mov %r15d,%ecx
3b: 80 e1 07 and $0x7,%cl
3e: 38 c1 cmp %al,%cl