[v6.1] INFO: task hung in __xfs_buf_submit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8e60a714ba3b Linux 6.1.132
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=108ab7b0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ebc45e145d6155ea
dashboard link: https://syzkaller.appspot.com/bug?extid=8ffb05c9df4022fc4424
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c8b8da8486ff/disk-8e60a714.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ad79748d8748/vmlinux-8e60a714.xz
kernel image: https://storage.googleapis.com/syzbot-assets/28699fcb5d47/bzImage-8e60a714.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8ffb05...@syzkaller.appspotmail.com

INFO: task syz.4.192:5122 blocked for more than 143 seconds.
Not tainted 6.1.132-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.192 state:D stack:25560 pid:5122 ppid:4245 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x143f/0x4570 kernel/sched/core.c:6561
schedule+0xbf/0x180 kernel/sched/core.c:6637
schedule_timeout+0xac/0x300 kernel/time/timer.c:1941
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x350/0x610 kernel/sched/completion.c:138
xfs_buf_iowait+0xd2/0x510 fs/xfs/xfs_buf.c:1611
__xfs_buf_submit+0x428/0x830 fs/xfs/xfs_buf.c:1691
xfs_buf_submit fs/xfs/xfs_buf.c:60 [inline]
xfs_buf_read_uncached+0x1f7/0x2d0 fs/xfs/xfs_buf.c:925
xfs_readsb+0x1a9/0x640 fs/xfs/xfs_mount.c:179
xfs_fs_fill_super+0x601/0x13a0 fs/xfs/xfs_super.c:1530
get_tree_bdev+0x3fe/0x620 fs/super.c:1366
vfs_get_tree+0x88/0x270 fs/super.c:1573
do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
do_mount fs/namespace.c:3399 [inline]
__do_sys_mount fs/namespace.c:3607 [inline]
__se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f426278d169
RSP: 002b:00007f4263524038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f42629a6160 RCX: 00007f426278d169
RDX: 0000200000000100 RSI: 00002000000000c0 RDI: 0000200000000040
RBP: 00007f426280e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f42629a6160 R15: 00007ffdc0444318
</TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8d32e910 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8d32f110 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
1 lock held by syslogd/3604:
2 locks held by getty/4003:
#0: ffff88814d6ce098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198
1 lock held by syz.4.192/5122:
#0: ffff88807cd940e0 (&type->s_umount_key#49/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.132-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1ca/0x430 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf88/0xfd0 kernel/hung_task.c:377
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.