INFO: task syz.3.37:6129 blocked for more than 143 seconds.
Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.37 state:D stack:27656 pid:6129 tgid:6124 ppid:5832 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:869 [inline]
vfs_rename+0x6d2/0xec0 fs/namei.c:5102
do_renameat2+0x878/0xc50 fs/namei.c:5286
__do_sys_rename fs/namei.c:5333 [inline]
__se_sys_rename fs/namei.c:5331 [inline]
__x64_sys_rename+0x82/0x90 fs/namei.c:5331
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: 0033:0x7f6e9198e929
RSP: 002b:00007f6e92857038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f6e91bb6080 RCX: 00007f6e9198e929
RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000200000000000
RBP: 00007f6e91a10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6e91bb6080 R15: 00007ffc1da517e8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5590:
#0: ffff888030de90a0 (&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/5834:
6 locks held by syz.3.37/6129:
#0: ffff88807e6ec428 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
#1: ffff88807e6ec738 (&type->s_vfs_rename_key#2){+.+.}-{4:4}, at: lock_rename fs/namei.c:3285 [inline]
#1: ffff88807e6ec738 (&type->s_vfs_rename_key#2){+.+.}-{4:4}, at: do_renameat2+0x37f/0xc50 fs/namei.c:5232
#2: ffff8880591e0f80 (&sb->s_type->i_mutex_key#29/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
#2: ffff8880591e0f80 (&sb->s_type->i_mutex_key#29/1){+.+.}-{4:4}, at: lock_two_directories+0x1a2/0x220 fs/namei.c:3261
#3: ffff8880591e15f0 (&sb->s_type->i_mutex_key#30/5){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
#3: ffff8880591e15f0 (&sb->s_type->i_mutex_key#30/5){+.+.}-{4:4}, at: lock_two_directories+0x1cc/0x220 fs/namei.c:3262
#4: ffff8880591e22d0 (&sb->s_type->i_mutex_key#31/2){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
#4: ffff8880591e22d0 (&sb->s_type->i_mutex_key#31/2){+.+.}-{4:4}, at: vfs_rename+0x651/0xec0 fs/namei.c:5100
#5: ffff8880591e15f0 (&sb->s_type->i_mutex_key#32){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
#5: ffff8880591e15f0 (&sb->s_type->i_mutex_key#32){++++}-{4:4}, at: vfs_rename+0x6d2/0xec0 fs/namei.c:5102
1 lock held by syz-executor/6344:
3 locks held by syz-executor/7182:
#0: ffff88807a7940e0 (&type->s_umount_key#64){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807a7940e0 (&type->s_umount_key#64){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88807a7940e0 (&type->s_umount_key#64){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff888044880278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:677
#2: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#2: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998
3 locks held by syz.0.328/8931:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
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: 7182 Comm: syz-executor Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 4e 39 80 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 8f 8c e1 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:ffffc9000ebe73b0 EFLAGS: 00000002
RAX: 1ffffffff33b2a00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff99d957d0 R08: ffff8880247f8237 R09: 1ffff110048ff046
R10: dffffc0000000000 R11: ffffffff854021a0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99d95540 R15: 0000000000000000
FS: 0000555587ad7500(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f707e3d5000 CR3: 0000000030db0000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x19e/0x2f0 drivers/tty/serial/8250/8250_port.c:2094
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
bch2_print_maybe_redirect fs/bcachefs/super.c:137 [inline]
__bch2_print+0x176/0x220 fs/bcachefs/super.c:156
__bch2_fs_read_only+0xe4/0x5b0 fs/bcachefs/super.c:284
bch2_fs_read_only+0x42a/0xb00 fs/bcachefs/super.c:367
__bch2_fs_stop+0x100/0x900 fs/bcachefs/super.c:678
generic_shutdown_super+0x132/0x2c0 fs/super.c:643
bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417
task_work_run+0x1d1/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8cf718fc57
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffce5aa31e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f8cf7210925 RCX: 00007f8cf718fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffce5aa32a0
RBP: 00007ffce5aa32a0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffce5aa4330
R13: 00007f8cf7210925 R14: 000000000004031c R15: 00007ffce5aa4370