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INFO: task hung in do_unlinkat

Status: auto-closed as invalid on 2019/02/24 11:49
First crash: 2171d, last: 2059d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in do_unlinkat (2) 1 507d 507d 0/1 auto-obsoleted due to no activity on 2023/03/27 07:50
upstream INFO: task hung in do_unlinkat (2) fs 4 1165d 1165d 0/26 auto-closed as invalid on 2021/05/17 08:41
upstream INFO: task hung in do_unlinkat exfat 34 1919d 2156d 0/26 closed as dup on 2018/10/27 13:26
upstream INFO: task hung in do_unlinkat (3) fs 2 883d 926d 0/26 closed as invalid on 2022/02/07 19:19
linux-4.19 INFO: task hung in do_unlinkat 1 637d 637d 0/1 auto-obsoleted due to no activity on 2022/11/17 10:56
upstream INFO: task hung in do_unlinkat (4) exfat 4 475d 582d 0/26 auto-obsoleted due to no activity on 2023/04/08 02:53

Sample crash report:
INFO: task syz-executor0:12037 blocked for more than 140 seconds.
      Not tainted 4.9.124-g09eb2ba #31
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29880 12037   3869 0x00000004
 ffff8801997cb000 0000000000000000 ffff8801cdde8fc0 ffff8801cdda3000
 ffff8801db221c18 ffff8801d6ee7ab8 ffffffff839f0afd ffffffff81237da7
 0000000000000000 ffff8801997cb8c0 0000000600000007 ffff8801db2224e8
Call Trace:
 [<ffffffff839f20ff>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff839fd738>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff839fd738>] rwsem_down_write_failed+0x598/0x990 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81eed907>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff8122e530>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff8122e530>] down_write_nested+0x60/0xa0 kernel/locking/rwsem.c:174
 [<ffffffff815af1d1>] inode_lock_nested include/linux/fs.h:801 [inline]
 [<ffffffff815af1d1>] do_unlinkat+0x2a1/0x680 fs/namei.c:4067
 [<ffffffff815b10ea>] SYSC_unlink fs/namei.c:4128 [inline]
 [<ffffffff815b10ea>] SyS_unlink+0x1a/0x20 fs/namei.c:4126
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff83a019d3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813689dc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813689dc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81428248>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3772:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839ffba2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff82125402>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
2 locks held by syz-executor0/12023:
 #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff815e50cf>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff815e50cf>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#23/1){+.+.+.}, at: [<ffffffff815ae7aa>] inode_lock_nested include/linux/fs.h:801 [inline]
 #1:  (&sb->s_type->i_mutex_key#23/1){+.+.+.}, at: [<ffffffff815ae7aa>] filename_create+0x17a/0x490 fs/namei.c:3639
2 locks held by syz-executor0/12037:
 #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff815e50cf>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff815e50cf>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#23/1){+.+.+.}, at: [<ffffffff815af1d1>] inode_lock_nested include/linux/fs.h:801 [inline]
 #1:  (&sb->s_type->i_mutex_key#23/1){+.+.+.}, at: [<ffffffff815af1d1>] do_unlinkat+0x2a1/0x680 fs/namei.c:4067
2 locks held by syz-executor0/12093:
 #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff815e50cf>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#16){.+.+.+}, at: [<ffffffff815e50cf>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#23/1){+.+.+.}, at: [<ffffffff815ae7aa>] inode_lock_nested include/linux/fs.h:801 [inline]
 #1:  (&sb->s_type->i_mutex_key#23/1){+.+.+.}, at: [<ffffffff815ae7aa>] filename_create+0x17a/0x490 fs/namei.c:3639

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.124-g09eb2ba #31
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d9277d08 ffffffff81eb95e9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b9fa0 ffff8801d9277d40
 ffffffff81ec4927 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb95e9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb95e9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ec4927>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ec48ba>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810ba0a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81368f74>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81368f74>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81368f74>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81368f74>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119f3cd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff83a01b9c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff83a00606

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/08/28 11:45 https://android.googlesource.com/kernel/common android-4.9 09eb2ba5ed0c 7ef1de9e .config console log report ci-android-49-kasan-gce-root
2018/08/13 04:18 https://android.googlesource.com/kernel/common android-4.9 9dc978d43ec7 7a88b141 .config console log report ci-android-49-kasan-gce-root
2018/08/06 11:54 https://android.googlesource.com/kernel/common android-4.9 8b21e85d919c 1beb8136 .config console log report ci-android-49-kasan-gce-root
2018/07/12 00:01 https://android.googlesource.com/kernel/common android-4.9 9e7903954483 2e0e3130 .config console log report ci-android-49-kasan-gce-root
2018/05/08 18:06 https://android.googlesource.com/kernel/common android-4.9 9731a2dab47e b88872ba .config console log report ci-android-49-kasan-gce-root
* Struck through repros no longer work on HEAD.