INFO: task syz-executor.0:6157 blocked for more than 143
INFO: task syz-executor.0:6157 blocked for more than 143 seconds.
Not tainted 6.13.0-rc7-next-20250114-syzkaller-gdab2734f8e9e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:27264 pid:6157 tgid:6156 ppid:6131 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5375 [inline]
__schedule+0x18f6/0x4cd0 kernel/sched/core.c:6762
__schedule_loop kernel/sched/core.c:6839 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6854
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6911
__mutex_lock_common kernel/locking/mutex.c:662 [inline]
__mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
bdev_release+0x17e/0x700 block/bdev.c:1086
blkdev_release+0x15/0x20 block/fops.c:660
__fput+0x3e9/0x9f0 fs/file_table.c:450
task_work_run+0x24f/0x310 kernel/task_work.c:227
get_signal+0x15f7/0x1750 kernel/signal.c:2790
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x4551e9
RSP: 002b:00007f3707e4d0d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 000000000054cf00 RCX: 00000000004551e9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00000000004a06fd R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000049f8fd
R13: 000000000000000b R14: 000000000054cf00 R15: 00007fff03c574b8
Showing all locks held in the system:
2 locks held by pr/ttyS0/17:
1 lock held by khungtaskd/31:
#0: ffffffff8e939e60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e939e60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e939e60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by getty/5589:
#0: ffff8880353e00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000330b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
1 lock held by udevd/6123:
#0: ffff8881437c84c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903
1 lock held by syz-executor.0/6157:
#0: ffff8881437c84c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x17e/0x700 block/bdev.c:1086
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.13.0-rc7-next-20250114-syzkaller-gdab2734f8e9e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0x1058/0x10a0 kernel/hung_task.c:399
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/ttyS0 Not tainted 6.13.0-rc7-next-20250114-syzkaller-gdab2734f8e9e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:409
Code: f0 ae 48 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 61 1c af fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c
RSP: 0018:ffffc900001678b8 EFLAGS: 00000002
RAX: 1ffffffff34e7800 RBX: ffffffff9a73c080 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff857699c6 R09: 1ffffffff1e306ec
R10: dffffc0000000000 R11: ffffffff85769980 R12: 0000000000000020
R13: 1ffffffff34e7862 R14: 00000000000003fd R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556939939680 CR3: 000000000e738000 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+0x1b1/0x320 drivers/tty/serial/8250/8250_port.c:2120
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3383 [inline]
serial8250_console_fifo_write+0xd5/0x390 drivers/tty/serial/8250/8250_port.c:3407
serial8250_console_write+0xf29/0x1360 drivers/tty/serial/8250/8250_port.c:3534
nbcon_emit_next_record+0x591/0xb60
nbcon_emit_one kernel/printk/nbcon.c:1115 [inline]
nbcon_kthread_func+0x6f3/0x940 kernel/printk/nbcon.c:1210
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244