syzbot

INFO: task syz-executor070:10344 blocked for more than 143 seconds.
      Not tainted 5.6.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor070 D26960 10344  10342 0x00004000
Call Trace:
 schedule+0xd0/0x2a0 kernel/sched/core.c:4154
 xlog_grant_head_wait+0x422/0xd40 fs/xfs/xfs_log.c:278
 xlog_grant_head_check+0x3b9/0x410 fs/xfs/xfs_log.c:340
 xfs_log_reserve+0x34b/0xac0 fs/xfs/xfs_log.c:465
 xfs_log_write_unmount_record+0x167/0x880 fs/xfs/xfs_log.c:890
 xfs_log_unmount_write fs/xfs/xfs_log.c:986 [inline]
 xfs_log_quiesce+0x397/0x510 fs/xfs/xfs_log.c:1049
 xfs_log_unmount+0x1d/0xb0 fs/xfs/xfs_log.c:1063
 xfs_mountfs+0x15ea/0x1f80 fs/xfs/xfs_mount.c:1022
 xfs_fc_fill_super+0x89b/0x1220 fs/xfs/xfs_super.c:1495
 get_tree_bdev+0x3f8/0x710 fs/super.c:1342
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 do_new_mount fs/namespace.c:2822 [inline]
 do_mount+0x1306/0x1a60 fs/namespace.c:3107
 __do_sys_mount fs/namespace.c:3316 [inline]
 __se_sys_mount fs/namespace.c:3293 [inline]
 __x64_sys_mount+0x18f/0x230 fs/namespace.c:3293
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44761a
Code: 6d 77 72 00 73 74 72 65 61 6d 20 77 72 69 74 65 72 00 77 65 20 68 61 64 20 61 20 66 69 6c 65 20 63 68 61 6e 67 65 20 6f 6e 20 <27> 25 73 27 0a 00 66 69 6c 65 20 25 64 20 72 65 61 64 20 25 6c 64
RSP: 002b:00007ffdbbec0258 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffdbbec0430 RCX: 000000000044761a
RDX: 00007ffdbbec02a0 RSI: 0000000020000000 RDI: 00007ffdbbec02c0
RBP: 0000000000000000 R08: 00007ffdbbec0300 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000402900
R13: 0000000000402990 R14: 0000000000000000 R15: 0000000000000000

Showing all locks held in the system:
1 lock held by khungtaskd/992:
 #0: ffffffff897accc0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5331
1 lock held by rsyslogd/10193:
 #0: ffff8880a779cda0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821
2 locks held by getty/10315:
 #0: ffff8880923ec090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900018332e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156
2 locks held by getty/10316:
 #0: ffff8880a03f9090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900018c32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156
2 locks held by getty/10317:
 #0: ffff888097399090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900018b32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156
2 locks held by getty/10318:
 #0: ffff8880a7df2090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900018932e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156
2 locks held by getty/10319:
 #0: ffff888099b3e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900018832e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156
2 locks held by getty/10320:
 #0: ffff88809f304090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900018a32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156
2 locks held by getty/10321:
 #0: ffff8880a2797090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffffc900018032e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156
1 lock held by syz-executor070/10344:
 #0: ffff88809faee0d8 (&type->s_umount_key#55/1){+.+.}, at: alloc_super+0x152/0x910 fs/super.c:229

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

NMI backtrace for cpu 0
CPU: 0 PID: 992 Comm: khungtaskd Not tainted 5.6.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xa8c/0x1010 kernel/hung_task.c:289
 kthread+0x357/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60