INFO: task syz-executor:12731 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21592 pid:12731 tgid:12731 ppid:1 task_flags:0x40014c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2834
sync_filesystem+0x17a/0x230 fs/sync.c:64
generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
kill_block_super+0x44/0x90 fs/super.c:1766
ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7395
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:961
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b46d8eba9
RSP: 002b:00007ffd65e523a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f3b46e11c77 RCX: 00007f3b46d8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000010 R08: 00007ffd65e50146 R09: 00007ffd65e53660
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd65e53660
R13: 00007f3b46e11c05 R14: 000055557a7284a8 R15: 00007ffd65e54730
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:8/4533:
#0: ffff888142ad4148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888142ad4148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000d787bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000d787bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff88805cbc2b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
#2: ffff88805cbc2b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1786 [inline]
#2: ffff88805cbc2b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024
#3: ffff88804cdd8c00 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x765/0x1740 fs/ext4/inode.c:810
2 locks held by getty/5618:
#0: ffff88814d2e40a0 (&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
1 lock held by syz-executor/5875:
#0: ffff88805ed4e0e0 (&type->s_umount_key#64){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88805ed4e0e0 (&type->s_umount_key#64){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88805ed4e0e0 (&type->s_umount_key#64){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
2 locks held by syz-executor/12731:
#0: ffff888079f7c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888079f7c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888079f7c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff888024ec47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff888024ec47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2832
2 locks held by kworker/u8:15/12988:
5 locks held by syz-executor/14435:
2 locks held by syz.8.1902/15348:
2 locks held by syz.7.1928/15438:
1 lock held by dhcpcd-run-hook/15465:
=============================================
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 08/18/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline]
RIP: 0010:lock_acquire+0x94/0x360 kernel/locking/lockdep.c:5844
Code: 0f 84 d7 01 00 00 83 3d b9 68 06 0e 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 b3 99 85 00 83 3d 9c 68 06 0e 00 <0f> 84 fa 00 00 00 65 8b 05 5f 82 03 11 85 c0 0f 85 eb 00 00 00 65
RSP: 0018:ffffffff8de07b00 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: de3fd02fe5aae200
RDX: 0000000000000000 RSI: ffffffff81b194bf RDI: 1ffffffff1bc2259
RBP: ffffffff81b1a4a7 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f474a7 R12: 0000000000000002
R13: ffffffff8de112c8 R14: 0000000000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffccef15348 CR3: 0000000077e3a000 CR4: 0000000000350ef0
Call Trace:
seqcount_lockdep_reader_access+0xcf/0x1c0 include/linux/seqlock.h:72
get_jiffies_update kernel/time/tick-sched.c:873 [inline]
tick_nohz_next_event+0x47/0x3e0 kernel/time/tick-sched.c:897
tick_nohz_idle_stop_tick+0x144/0xc60 kernel/time/tick-sched.c:1218
cpuidle_idle_call kernel/sched/idle.c:188 [inline]
do_idle+0x1e3/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:744
start_kernel+0x3a9/0x410 init/main.c:1097
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x147