INFO: task hung in sync_inodes

[upstream] INFO: task hung in sync_inodes_sb
Status: closed as dup on 2018/09/08 15:37
Reported-by: syzbot+9af766081cb7e2db43b0@syzkaller.appspotmail.com
First: 127d, last: 2d17h

Duplicate of:
Title	Repro	Count	Last	Reported
INFO: task hung in __blkdev_get (2)		6	20d	15d

Sample crash report:

binder_alloc: 17353: binder_alloc_buf size 4294967296 failed, no address space
binder_alloc: allocated: 0 (num: 0 largest: 0), free: 12288 (num: 1 largest: 12288)
binder: 17353:17354 transaction failed 29201/-28, size 0-0 line 2971
INFO: task syz-executor4:17376 blocked for more than 120 seconds.
      Not tainted 4.17.0-rc5+ #58
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D25544 17376   9129 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2859 [inline]
 __schedule+0x801/0x1e30 kernel/sched/core.c:3501
 schedule+0xef/0x430 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0xe38/0x17f0 kernel/locking/mutex.c:893
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
 wait_sb_inodes+0x1c9/0xc20 fs/fs-writeback.c:2246
 sync_inodes_sb+0x32f/0x450 fs/fs-writeback.c:2426
 sync_inodes_one_sb+0x59/0x70 fs/sync.c:74
 iterate_supers+0x149/0x290 fs/super.c:620
 ksys_sync+0xe6/0x1d0 fs/sync.c:113
 __ia32_sys_sync+0xe/0x20 fs/sync.c:124
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455a09
RSP: 002b:00007f6273ddbc68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f6273ddc6d4 RCX: 0000000000455a09
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000072c160 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000070a R14: 00000000006fe990 R15: 0000000000000004

Showing all locks held in the system:
2 locks held by khungtaskd/893:
 #0: 00000000b963e1e8 (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0: 00000000b963e1e8 (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249
 #1: 000000007900d082 (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4388:
 #0: 000000009b65db08 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1a9/0x1e0 fs/file.c:766
2 locks held by getty/4478:
 #0: 00000000fce50cc0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000e8a3cab8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4479:
 #0: 000000001a2edab9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000e4c418c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4480:
 #0: 0000000091cd0093 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000007aa76a1e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4481:
 #0: 00000000da07d0d1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 0000000005c042ab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4482:
 #0: 00000000342323ea (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000dd293eac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4483:
 #0: 000000008f1b7e37 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000000e1c9138 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4484:
 #0: 00000000935b4fe7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000001166d44b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by syz-executor4/17376:
 #0: 00000000bbb76ecc (&type->s_umount_key#29){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:618
 #1: 00000000b3d5554c (&s->s_sync_lock){+.+.}, at: wait_sb_inodes+0x1c9/0xc20 fs/fs-writeback.c:2246

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

NMI backtrace for cpu 1
CPU: 1 PID: 893 Comm: khungtaskd Not tainted 4.17.0-rc5+ #58
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+0x1b9/0x294 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
 check_hung_task kernel/hung_task.c:132 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0xc10/0xf60 kernel/hung_task.c:249
 kthread+0x345/0x410 kernel/kthread.c:240
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54

All crashes (6):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Maintainers
ci-upstream-kasan-gce-root	2018/05/19 16:04	upstream	73fcb1a3	849705db	.config	log	report	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-selinux-root	2018/09/21 07:24	upstream	234b69e3	37079712	.config	log	report	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-root	2018/09/02 14:32	upstream	360bd62d	a4718693	.config	log	report	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-kasan-gce-root	2018/08/14 23:42	upstream	d0055f35	0e6dcb88	.config	log	report	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-linux-next-kasan-gce-root	2018/09/04 22:05	linux-next	f2b6e66e	a4718693	.config	log	report	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk
ci-upstream-linux-next-kasan-gce-root	2018/08/23 09:08	linux-next	455fb5ec	95b5c82b	.config	log	report	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk