INFO: task syz.4.85:6248 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.85 state:D stack:28792 pid:6248 tgid:6227 ppid:5806 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
io_schedule+0x80/0xe0 kernel/sched/core.c:7832
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:375
jfs_rmdir+0x234/0x860 fs/jfs/namei.c:364
vfs_rmdir+0x400/0x6f0 fs/namei.c:5338
filename_rmdir+0x292/0x520 fs/namei.c:5393
__do_sys_rmdir fs/namei.c:5416 [inline]
__se_sys_rmdir+0x2e/0x140 fs/namei.c:5413
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: 0033:0x7f593fb4c799
RSP: 002b:00007f593dd85028 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f593fdc6090 RCX: 00007f593fb4c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000002c0
RBP: 00007f593fbe2bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f593fdc6128 R14: 00007f593fdc6090 R15: 00007ffc14623418
Showing all locks held in the system:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:7/1041:
8 locks held by kworker/u8:9/1281:
4 locks held by kworker/u8:11/3466:
3 locks held by udevd/5165:
2 locks held by getty/5554:
#0: ffff8880376670a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by udevd/5794:
1 lock held by syz-executor/5795:
4 locks held by udevd/5801:
3 locks held by kworker/0:6/5901:
2 locks held by udevd/5983:
#0: ffffffff8e3d9e78 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x11a/0x360 fs/btrfs/super.c:2265
#1: ffff888039d96cc8 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: btrfs_skip_registration fs/btrfs/volumes.c:1421 [inline]
#1: ffff888039d96cc8 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: btrfs_scan_one_device+0x137/0x680 fs/btrfs/volumes.c:1488
3 locks held by syz.4.85/6248:
#0: ffff888031ca8480 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff888060061938 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff888060061938 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff888060061938 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff888060061938 (&type->i_mutex_dir_key#14/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386
#2: ffff888060074038 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#2: ffff888060074038 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: vfs_rmdir+0x109/0x6f0 fs/namei.c:5323
2 locks held by syz.5.607/8481:
#0: ffff888039d96cc8 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: btrfs_trim_free_extents fs/btrfs/extent-tree.c:6659 [inline]
#0: ffff888039d96cc8 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: btrfs_trim_fs+0x63d/0x19d0 fs/btrfs/extent-tree.c:6823
#1: ffff888035de4e98 (&fs_info->chunk_mutex){+.+.}-{4:4}, at: btrfs_trim_free_extents_throttle fs/btrfs/extent-tree.c:6552 [inline]
#1: ffff888035de4e98 (&fs_info->chunk_mutex){+.+.}-{4:4}, at: btrfs_trim_free_extents fs/btrfs/extent-tree.c:6666 [inline]
#1: ffff888035de4e98 (&fs_info->chunk_mutex){+.+.}-{4:4}, at: btrfs_trim_fs+0x885/0x19d0 fs/btrfs/extent-tree.c:6823
3 locks held by syz.0.611/8534:
3 locks held by syz.6.610/8533:
2 locks held by syz.3.613/8539:
=============================================
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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 8e ed 94 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ef 05 fb fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001679d0 EFLAGS: 00000202
RAX: 1ffffffff332a400 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff99952730 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff852f6230 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff999524a0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812633d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd5e6534000 CR3: 000000005a0b0000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3163 [inline]
console_flush_one_record+0x68b/0xb90 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+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245