[v6.1] INFO: task hung in nbd_add_socket

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fa74641fb6b9 Linux 6.1.29
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=110471d9280000
kernel config: https://syzkaller.appspot.com/x/.config?x=fac5c36c2b16009f
dashboard link: https://syzkaller.appspot.com/bug?extid=3e648ac717510d6c66c9
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=174b17d6280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1021382e280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/3e78f005d7f8/disk-fa74641f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6527fcf66401/vmlinux-fa74641f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c5e0d5f8b434/bzImage-fa74641f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3e648a...@syzkaller.appspotmail.com

INFO: task syz-executor189:3633 blocked for more than 143 seconds.
Not tainted 6.1.29-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor189 state:D stack:26936 pid:3633 ppid:3579 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0x132c/0x4330 kernel/sched/core.c:6554
schedule+0xbf/0x180 kernel/sched/core.c:6630
blk_mq_freeze_queue_wait+0xf8/0x180 block/blk-mq.c:180
nbd_add_socket+0x17c/0x8f0 drivers/block/nbd.c:1121
__nbd_ioctl drivers/block/nbd.c:1464 [inline]
nbd_ioctl+0x261/0xe70 drivers/block/nbd.c:1521
blkdev_ioctl+0x3a9/0x760 block/ioctl.c:615
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4382c5a249
RSP: 002b:00007f4382c07308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4382cde408 RCX: 00007f4382c5a249
RDX: 0000000000000004 RSI: 000000000000ab00 RDI: 0000000000000003
RBP: 00007f4382cde400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4382cde40c
R13: 00007f4382cab1a4 R14: 64626e2f7665642f R15: 0000000000022000
</TASK>
INFO: task syz-executor189:3634 blocked for more than 143 seconds.
Not tainted 6.1.29-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor189 state:D stack:28664 pid:3634 ppid:3579 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0x132c/0x4330 kernel/sched/core.c:6554
schedule+0xbf/0x180 kernel/sched/core.c:6630
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6689
__mutex_lock_common+0xe2b/0x2520 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
nbd_ioctl+0x149/0xe70 drivers/block/nbd.c:1514
blkdev_ioctl+0x3a9/0x760 block/ioctl.c:615
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4382c5a249
RSP: 002b:00007f4382be6308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4382cde418 RCX: 00007f4382c5a249
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f4382cde410 R08: 00007f4382be6700 R09: 0000000000000000
R10: 00007f4382be6700 R11: 0000000000000246 R12: 00007f4382cde41c
R13: 00007f4382cab1a4 R14: 64626e2f7665642f R15: 0000000000022000
</TASK>
INFO: task syz-executor189:3635 blocked for more than 143 seconds.
Not tainted 6.1.29-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor189 state:D stack:29096 pid:3635 ppid:3579 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0x132c/0x4330 kernel/sched/core.c:6554
schedule+0xbf/0x180 kernel/sched/core.c:6630
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6689
__mutex_lock_common+0xe2b/0x2520 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
nbd_ioctl+0x149/0xe70 drivers/block/nbd.c:1514
blkdev_ioctl+0x3a9/0x760 block/ioctl.c:615
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4382c5a249
RSP: 002b:00007f4382bc5308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4382cde428 RCX: 00007f4382c5a249
RDX: 0000000000010000 RSI: 000000000000ab07 RDI: 0000000000000003
RBP: 00007f4382cde420 R08: 00007f4382bc5700 R09: 0000000000000000
R10: 00007f4382bc5700 R11: 0000000000000246 R12: 00007f4382cde42c
R13: 00007f4382cab1a4 R14: 64626e2f7665642f R15: 0000000000022000
</TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cf274b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cf27cb0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
#0: ffffffff8cf272e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by klogd/2988:
#0: ffff8880b9939dd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
2 locks held by getty/3308:
#0: ffff88814b0cd098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2177
1 lock held by syz-executor189/3633:
#0: ffff888142fe0198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x149/0xe70 drivers/block/nbd.c:1514
1 lock held by syz-executor189/3634:
#0: ffff888142fe0198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x149/0xe70 drivers/block/nbd.c:1514
1 lock held by syz-executor189/3635:
#0: ffff888142fe0198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x149/0xe70 drivers/block/nbd.c:1514

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.29-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
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+0x1b0/0x3f0 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+0xf18/0xf60 kernel/hung_task.c:377
kthread+0x26e/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted 6.1.29-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4571 [inline]
RIP: 0010:__lock_acquire+0xd71/0x1f80 kernel/locking/lockdep.c:5040
Code: e8 48 c1 e8 03 80 3c 38 00 74 12 48 89 ef e8 e6 33 76 00 48 bf 00 00 00 00 00 fc ff df 4c 89 7d 00 48 8b 44 24 28 0f b6 04 38 <84> c0 0f 85 36 0b 00 00 41 8b 1c 24 48 85 db 74 58 83 fb 31 0f 83
RSP: 0018:ffffc900000e76a0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88813fe38ad0 RCX: ffffffff8169d5bf
RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000
RBP: ffff88813fe38b80 R08: dffffc0000000000 R09: fffffbfff2050845
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fe38ad8
R13: 0000000000000000 R14: ffff88813fe38ba0 R15: cdf6fcfc9f7cb4f8
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a57581fef0 CR3: 000000000cc8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
__mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
arch_jump_label_transform_queue+0x40/0xd0 arch/x86/kernel/jump_label.c:136
__jump_label_update+0x177/0x3a0 kernel/jump_label.c:447
static_key_disable_cpuslocked+0xca/0x1b0 kernel/jump_label.c:207
static_key_disable+0x16/0x20 kernel/jump_label.c:215
toggle_allocation_gate+0x3e0/0x480 mm/kfence/core.c:818
process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2289
worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436
kthread+0x26e/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.113 msecs


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to change bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup