INFO: task hung in blkdev_issue_zeroout

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 4a739e35 Merge 4.14.101 into android-4.14
git tree: android-4.14
console output: https://syzkaller.appspot.com/x/log.txt?x=154b17a8c00000
kernel config: https://syzkaller.appspot.com/x/.config?x=fa88ec8e8cdb00c8
dashboard link: https://syzkaller.appspot.com/bug?extid=a3122a759673ff462549
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a3122a...@syzkaller.appspotmail.com

INFO: task syz-executor.2:18472 blocked for more than 140 seconds.
Not tainted 4.14.101+ #14
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2 D28528 18472 10824 0x00000004
Call Trace:
schedule+0x92/0x1c0 kernel/sched/core.c:3495
schedule_timeout+0x736/0xe80 kernel/time/timer.c:1721
io_schedule_timeout+0x26/0x80 kernel/sched/core.c:5090
do_wait_for_common kernel/sched/completion.c:91 [inline]
__wait_for_common kernel/sched/completion.c:112 [inline]
wait_for_common_io.constprop.0+0x274/0x3b0 kernel/sched/completion.c:129
submit_bio_wait+0x107/0x170 block/bio.c:954
blkdev_issue_zeroout+0x217/0x4c0 block/blk-lib.c:408
blkdev_fallocate+0x297/0x3b0 fs/block_dev.c:2017
vfs_fallocate+0x348/0x790 fs/open.c:328
SYSC_fallocate fs/open.c:351 [inline]
SyS_fallocate+0x4a/0x80 fs/open.c:345
do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289

Showing all locks held in the system:
1 lock held by khungtaskd/23:
#0: (tasklist_lock){.+.+}, at: [<ffffffffa9c00cfc>]
debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
2 locks held by getty/1755:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffffaa738302>]
tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffffaa733727>]
n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.0/14541:
#0: (&sig->cred_guard_mutex){+.+.}, at: [<ffffffffa9f6d6b1>]
prepare_bprm_creds+0x51/0x110 fs/exec.c:1389
1 lock held by syz-executor.0/14563:
#0: (&sig->cred_guard_mutex){+.+.}, at: [<ffffffffa9f6d6b1>]
prepare_bprm_creds+0x51/0x110 fs/exec.c:1389

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

NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.101+ #14
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xb9/0x10e lib/dump_stack.c:53
nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9902 Comm: loop2 Not tainted 4.14.101+ #14
task: ffff88817d635e00 task.stack: ffff8881c9378000
RIP: 0010:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:100
RSP: 0018:ffff8881d7607fc0 EFLAGS: 00000046
RAX: ffffffffa9a9aa90 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 1ffffffff579852e RSI: 0000000000000000 RDI: 00000000000000b0
RBP: ffffffffabcc2880 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881d7600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000047007d CR3: 00000001f1426003 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
apic_eoi arch/x86/include/asm/apic.h:400 [inline]
ack_APIC_irq arch/x86/include/asm/apic.h:444 [inline]
entering_ack_irq arch/x86/include/asm/apic.h:636 [inline]
smp_apic_timer_interrupt+0x7a/0x620 arch/x86/kernel/apic/apic.c:1060
apic_timer_interrupt+0x84/0x90 arch/x86/entry/entry_64.S:787
</IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:778
[inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160
[inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x59/0x70
kernel/locking/spinlock.c:192
RSP: 0018:ffff8881c937f798 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000007 RBX: 0000000000000202 RCX: 1ffff1102fac6cca
RDX: 0000000000000000 RSI: ffff88817d636658 RDI: 0000000000000202
RBP: ffffffffad438458 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000202
R13: 0000000000000171 R14: 0000000000000000 R15: dffffc0000000000
spin_unlock_irqrestore include/linux/spinlock.h:372 [inline]
avc_reclaim_node security/selinux/avc.c:539 [inline]
avc_alloc_node security/selinux/avc.c:557 [inline]
avc_alloc_node+0x28d/0x3c0 security/selinux/avc.c:545
avc_insert security/selinux/avc.c:668 [inline]
avc_compute_av+0x17c/0x550 security/selinux/avc.c:974
Code: 83 3d ac ba da 02 01 77 02 5d c3 89 ef 5d e9 71 e7 fe ff 48 c7 c7 20
65 84 ac e8 84 e6 48 00 eb df 66 90 89 ff 89 b7 00 d0 5f ff <c3> 0f 1f 80
00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb


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[syzbot]

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