INFO: task syz.9.5557:23843 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.5557 state:D stack:28360 pid:23843 tgid:23841 ppid:21982 task_flags:0x400040 flags:0x00004006
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
io_schedule+0x80/0xd0 kernel/sched/core.c:7903
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3124
__filemap_fdatawait_range+0x147/0x230 mm/filemap.c:539
filemap_fdatawait_keep_errors+0x31/0xd0 mm/filemap.c:633
wait_sb_inodes fs/fs-writeback.c:2715 [inline]
sync_inodes_sb+0x7a9/0xa10 fs/fs-writeback.c:2837
__iterate_supers+0x13d/0x290 fs/super.c:924
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
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: 0033:0x7fa0d138ebe9
RSP: 002b:00007fa0d2158038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fa0d15c5fa0 RCX: 00007fa0d138ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa0d15c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa0d15c6038 R14: 00007fa0d15c5fa0 R15: 00007fffe33234a8
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644
1 lock held by khungtaskd/31:
#0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:4/59:
#0: ffff888146ec4148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888146ec4148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000210fbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000210fbc0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
2 locks held by getty/5618:
#0: ffff8880338d60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz.1.3720/17746:
#0: ffff88807c046428 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline]
#0: ffff88807c046428 (sb_writers#21){.+.+}-{0:0}, at: vfs_writev+0x288/0x960 fs/read_write.c:1055
#1: ffff888040470148 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: netfs_start_io_write+0xd8/0x100 fs/netfs/locking.c:112
1 lock held by syz-executor/22997:
#0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
2 locks held by syz.9.5557/23843:
#0: ffff88807c0460e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88807c0460e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
#1: ffff88807c046950 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2654 [inline]
#1: ffff88807c046950 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x255/0xa10 fs/fs-writeback.c:2837
=============================================
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 08/14/2025
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+0x3fc/0x770 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: 5228 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
RIP: 0010:rcu_rdp_cpu_online kernel/rcu/tree.c:3994 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online+0x87/0x120 kernel/rcu/tree.c:4035
Code: 3c 30 00 74 08 48 89 df e8 c6 76 7c 00 48 8b 03 48 8d 98 80 2f a2 92 48 8d b8 a8 2f a2 92 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <74> 05 e8 a2 76 7c 00 4c 8b 7b 28 48 83 c3 20 48 89 d8 48 c1 e8 03
RSP: 0018:ffffc90003e8fc48 EFLAGS: 00000246
RAX: 1ffff110170c75f5 RBX: ffff8880b863af80 RCX: cca22278c8a93b00
RDX: ffff88807df91e00 RSI: ffffffff8be33860 RDI: ffff8880b863afa8
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff825e36fc
R10: dffffc0000000000 R11: ffffed1009f6a001 R12: dffffc0000000000
R13: ffff88801da995a0 R14: dffffc0000000000 R15: ffff888140a83000
FS: 00007fe137215880(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555947a9608 CR3: 000000007da0f000 CR4: 0000000000350ef0
Call Trace:
rcu_read_lock_held_common kernel/rcu/update.c:113 [inline]
rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349
kernfs_root+0xf6/0x230 fs/kernfs/kernfs-internal.h:76
kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline]
kernfs_parent+0x51/0x190 fs/kernfs/kernfs-internal.h:133
kernfs_get_target_path fs/kernfs/symlink.c:65 [inline]
kernfs_getlink fs/kernfs/symlink.c:122 [inline]
kernfs_iop_get_link+0x1dc/0x6c0 fs/kernfs/symlink.c:140
vfs_readlink+0x24d/0x550 fs/namei.c:5375
do_readlinkat+0x215/0x500 fs/stat.c:590
__do_sys_readlink fs/stat.c:613 [inline]
__se_sys_readlink fs/stat.c:610 [inline]
__x64_sys_readlink+0x7f/0x90 fs/stat.c:610
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: 0033:0x7fe136b153a7
Code: 00 00 90 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 00 31 c9 e8 8a 20 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 21 ba 0d 00 f7 d8 64 89 02 48
RSP: 002b:00007ffdfa2127a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffdfa212ff0 RCX: 00007fe136b153a7
RDX: 0000000000000400 RSI: 00007ffdfa212bb0 RDI: 00007ffdfa2127b0
RBP: 0000000000000200 R08: 00005610ac283c29 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffdfa2127b0
R13: 00007ffdfa212bb0 R14: 0000000000000000 R15: 00007ffdfa213500