INFO: task syz.3.419:10395 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.419 state:D stack:24808 pid:10395 tgid:10377 ppid:5794 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
inode_lock_nested include/linux/fs.h:1073 [inline]
__start_dirop fs/namei.c:2923 [inline]
start_dirop fs/namei.c:2934 [inline]
filename_create+0x200/0x370 fs/namei.c:4922
filename_mkdirat+0xd2/0x520 fs/namei.c:5259
__do_sys_mkdirat fs/namei.c:5287 [inline]
__se_sys_mkdirat+0x35/0x150 fs/namei.c:5284
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: 0033:0x7fb6f43eb607
RSP: 002b:00007fb6f261ce58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fb6f261cee0 RCX: 00007fb6f43eb607
RDX: 00000000000001ff RSI: 0000200000000b40 RDI: 00000000ffffff9c
RBP: 0000200000000b00 R08: 00002000000000c0 R09: 0000000000000000
R10: 0000200000000b00 R11: 0000000000000246 R12: 0000200000000b40
R13: 00007fb6f261cea0 R14: 0000000000000000 R15: 0000000000000000
Showing all locks held in the system:
6 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/38:
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
7 locks held by kworker/u8:6/163:
8 locks held by kworker/u8:9/1021:
2 locks held by getty/5552:
#0: ffff888037b970a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by udevd/5793:
2 locks held by udevd/5807:
#0: ffff8880114bc480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff8880389ba498 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff8880389ba498 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff8880389ba498 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff8880389ba498 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_unlinkat+0x2ad/0x610 fs/namei.c:5521
2 locks held by udevd/5811:
2 locks held by udevd/5812:
#0: ffff8880114bc480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff8880389ba498 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff8880389ba498 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3756 [inline]
#1: ffff8880389ba498 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3852
7 locks held by syz.3.419/10382:
2 locks held by syz.3.419/10395:
#0: ffff888025d82480 (sb_writers#4){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff8880405bcbf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff8880405bcbf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff8880405bcbf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff8880405bcbf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922
6 locks held by syz-executor/10591:
#0: ffff888051f380d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888051f380d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888051f380d0 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
#1: ffff8880572b31e0 (btrfs_trans_completed){++++}-{0:0}, at: btrfs_commit_transaction+0x1a2/0x31a0 fs/btrfs/transaction.c:2231
#2: ffff8880572b31b8 (btrfs_trans_super_committed){.+.+}-{0:0}, at: btrfs_commit_transaction+0x1a2/0x31a0 fs/btrfs/transaction.c:2231
#3: ffff8880572b0d18 (&fs_info->tree_log_mutex){+.+.}-{4:4}, at: btrfs_commit_transaction+0x1c4c/0x31a0 fs/btrfs/transaction.c:2553
#4: ffff888060d6a0c8 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: write_all_supers+0x126f/0x45c0 fs/btrfs/disk-io.c:4060
#5: ffff8880252c6858 (&fq->mq_flush_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline]
#5: ffff8880252c6858 (&fq->mq_flush_lock){+.+.}-{3:3}, at: blk_insert_flush+0x357/0x5a0 block/blk-flush.c:446
1 lock held by syz.4.748/12890:
#0: ffff88805a0ca480 (sb_writers#16){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff88805a0ca480 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
1 lock held by syz.7.753/12929:
#0: ffff8880695c80d0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
1 lock held by udevadm/12958:
2 locks held by udevadm/12960:
4 locks held by syz-executor/12961:
1 lock held by syz.9.756/12963:
=============================================
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 02/12/2026
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:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 3e 5d 02 e9 13 c4 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 f3 6c 26 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:ffffffff8da07dc0 EFLAGS: 00000242
RAX: 000000000009b0c1 RBX: ffffffff81996f6a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d561b0a RDI: ffffffff8ba66b00
RBP: ffffffff8da07eb0 R08: ffff8880b8833f1b R09: 1ffff110171067e3
R10: dffffc0000000000 R11: ffffed10171067e4 R12: 0000000000000000
R13: 1ffffffff1b605d8 R14: 0000000000000000 R15: 1ffffffff1b605d8
FS: 0000000000000000(0000) GS:ffff88812633c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f40631dda08 CR3: 00000000344f8000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
rest_init+0x2de/0x300 init/main.c:760
start_kernel+0x385/0x3d0 init/main.c:1210
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147