[syzbot] [block?] INFO: task hung in bdev_release

syzbot
2023-11-30T15:02:41Z

Hello,

syzbot found the following issue on:

HEAD commit: 8c9660f65153 Add linux-next specific files for 20231124
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=14c8a334e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=ca1e8655505e280
dashboard link: https://syzkaller.appspot.com/bug?extid=4da851837827326a7cd4
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=119809d0e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13930542e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/345ed4af3a0d/disk-8c9660f6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/191053c69d57/vmlinux-8c9660f6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/aac7ee5e55e0/bzImage-8c9660f6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4da851837827326a7cd4@syzkaller.appspotmail.com

INFO: task syz-executor136:5067 blocked for more than 143 seconds.
Not tainted 6.7.0-rc2-next-20231124-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor136 state:D stack:26736 pid:5067 tgid:5066 ppid:5064 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5399 [inline]
__schedule+0xf15/0x5c00 kernel/sched/core.c:6726
__schedule_loop kernel/sched/core.c:6801 [inline]
schedule+0xe7/0x270 kernel/sched/core.c:6816
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6873
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x5b4/0x9c0 kernel/locking/mutex.c:747
bdev_release+0xcd/0xa90 block/bdev.c:967
blkdev_release+0x37/0x50 block/fops.c:616
__fput+0x270/0xbb0 fs/file_table.c:394
task_work_run+0x14c/0x240 kernel/task_work.c:180
ptrace_notify+0x10a/0x130 kernel/signal.c:2390
ptrace_report_syscall include/linux/ptrace.h:411 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline]
syscall_exit_work kernel/entry/common.c:251 [inline]
syscall_exit_to_user_mode_prepare+0x122/0x230 kernel/entry/common.c:278
__syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
syscall_exit_to_user_mode+0xe/0x60 kernel/entry/common.c:296
do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:88
entry_SYSCALL_64_after_hwframe+0x62/0x6a
RIP: 0033:0x7f7015ea8479
RSP: 002b:00007f7015e66218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f7015f2f328 RCX: 00007f7015ea8479
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000005
RBP: 00007f7015f2f320 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7015f2f32c
R13: 00007f7015efc18c R14: 64626e2f7665642f R15: 00000000ffffff43
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cfacf60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline]
#0: ffffffff8cfacf60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
#0: ffffffff8cfacf60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613
2 locks held by getty/4817:
#0: ffff88802ae300a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc4/0x1490 drivers/tty/n_tty.c:2201
1 lock held by udevd/5057:
#0: ffff888143bbf4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open_by_dev+0x27c/0xed0 block/bdev.c:857
1 lock held by syz-executor136/5067:
#0: ffff888143bbf4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0xcd/0xa90 block/bdev.c:967

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc2-next-20231124-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
nmi_cpu_backtrace+0x277/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf86/0x1210 kernel/hung_task.c:379
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 59 Comm: kworker/u4:4 Not tainted 6.7.0-rc2-next-20231124-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline]
RIP: 0010:wrmsrl arch/x86/include/asm/msr.h:262 [inline]
RIP: 0010:native_x2apic_icr_write arch/x86/include/asm/apic.h:216 [inline]
RIP: 0010:__x2apic_send_IPI_dest arch/x86/kernel/apic/x2apic_phys.c:113 [inline]
RIP: 0010:x2apic_send_IPI+0x96/0xe0 arch/x86/kernel/apic/x2apic_phys.c:50
Code: 8b 13 0f ae f0 0f ae e8 b9 00 04 00 00 41 83 fc 02 44 89 e0 48 0f 44 c1 48 c1 e2 20 b9 30 08 00 00 48 09 d0 48 c1 ea 20 0f 30 <66> 90 5b 5d 41 5c c3 5b 31 d2 48 89 c6 bf 30 08 00 00 5d 41 5c e9
RSP: 0018:ffffc900015a7900 EFLAGS: 00000202
RAX: 00000001000000fb RBX: ffff8880b9921a2c RCX: 0000000000000830
RDX: 0000000000000001 RSI: 00000000000000fb RDI: ffffffff8ca75a68
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000006 R12: 00000000000000fb
R13: 000000000003bccc R14: 0000000000000001 R15: ffff8880b983d8c0
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055750a5bb680 CR3: 000000000cd78000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:101 [inline]
send_call_function_single_ipi kernel/smp.c:117 [inline]
smp_call_function_many_cond+0x12ef/0x1570 kernel/smp.c:837
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2008 [inline]
text_poke_bp_batch+0x655/0x750 arch/x86/kernel/alternative.c:2218
text_poke_flush arch/x86/kernel/alternative.c:2409 [inline]
text_poke_flush arch/x86/kernel/alternative.c:2406 [inline]
text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2416
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x1d7/0x400 kernel/jump_label.c:829
static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205
static_key_enable+0x1a/0x20 kernel/jump_label.c:218
toggle_allocation_gate mm/kfence/core.c:830 [inline]
toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:822
process_one_work+0x8a4/0x15f0 kernel/workqueue.c:2633
process_scheduled_works kernel/workqueue.c:2706 [inline]
worker_thread+0x8b6/0x1290 kernel/workqueue.c:2787
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
</TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.905 msecs

---
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