[syzbot] INFO: task can't die in submit_bio_wait (2)

[syzbot <syzbot+b8c45d4034039b7ce03e@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    ef6b35306dd8 Add linux-next specific files for 20220204
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10ed552c700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e0431e0b00810b4f
dashboard link: https://syzkaller.appspot.com/bug?extid=b8c45d4034039b7ce03e
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=108cb306700000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10bed71c700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b8c45d4034039b7ce03e@syzkaller.appspotmail.com

INFO: task syz-executor157:3633 can't die for more than 143 seconds.
task:syz-executor157 state:D stack:28120 pid: 3633 ppid:  3629 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5000 [inline]
 __schedule+0xab2/0x4db0 kernel/sched/core.c:6309
 schedule+0xd2/0x1f0 kernel/sched/core.c:6381
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 io_schedule_timeout+0xcb/0x140 kernel/sched/core.c:8406
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common_io kernel/sched/completion.c:123 [inline]
 wait_for_completion_io_timeout+0x16f/0x280 kernel/sched/completion.c:191
 submit_bio_wait+0x158/0x230 block/bio.c:1308
 blkdev_issue_flush+0x95/0xd0 block/blk-flush.c:464
 blkdev_fsync+0x68/0xa0 block/fops.c:471
 vfs_fsync_range fs/sync.c:188 [inline]
 vfs_fsync fs/sync.c:202 [inline]
 do_fsync fs/sync.c:212 [inline]
 __do_sys_fdatasync fs/sync.c:225 [inline]
 __se_sys_fdatasync fs/sync.c:223 [inline]
 __x64_sys_fdatasync+0xc5/0x140 fs/sync.c:223
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fcb854986d9
RSP: 002b:00007ffd575ac058 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: ffffffffffffffda RBX: 0000000000076c12 RCX: 00007fcb854986d9
RDX: 00007fcb854986d9 RSI: 0000000000000005 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffd575ac1f8 R09: 00007ffd575ac1f8
R10: 00007ffd575ac1f8 R11: 0000000000000246 R12: 00007ffd575ac06c
R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6463
2 locks held by getty/3275:
 #0: ffff88807f051098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
 #1: ffffc90002b662e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077

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