syzbot


BUG: Dentry still in use [unmount of tmpfs tmpfs]

Status: upstream: reported C repro on 2021/02/01 05:18
Reported-by: syzbot+d4aeb09e24a56864701f@syzkaller.appspotmail.com
First crash: 731d, last: 560d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 BUG: Dentry still in use [unmount of ext4 loop0] C error 63 428d 466d 0/2 closed as dup on 2021/10/28 13:08
android-5-10 BUG: Dentry still in use in unmount C done 1184 344d 356d 2/2 fixed on 2022/02/25 03:20
android-54 BUG: Dentry still in use [unmount of ramfs ramfs] C 476 363d 685d 0/2 upstream: reported C repro on 2021/03/19 07:18
upstream BUG: Dentry still in use [unmount of tmpfs tmpfs] 2 1335d 1334d 13/24 fixed on 2019/07/10 21:40
upstream BUG: Dentry still in use [unmount of tmpfs tmpfs] (2) 3 811d 807d 0/24 auto-closed as invalid on 2021/02/11 21:17

Sample crash report:
BUG: Dentry 000000009fb05929{i=0,n=.index}  still in use (1) [unmount of tmpfs tmpfs]
------------[ cut here ]------------
WARNING: CPU: 1 PID: 364 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 364 Comm: syz-executor417 Not tainted 5.4.93-syzkaller-00590-g1e5f5a14faba #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+0x1dd/0x24e lib/dump_stack.c:118
 panic+0x285/0x750 kernel/panic.c:221
 __warn+0x1fd/0x200 kernel/panic.c:582
 report_bug+0x390/0x4d0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap arch/x86/kernel/traps.c:272 [inline]
 do_invalid_op+0x6e/0x110 arch/x86/kernel/traps.c:291
 invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:1029
RIP: 0010:umount_check+0x179/0x1c0 fs/dcache.c:1588
Code: ff 4c 8b 0b 48 81 c5 20 04 00 00 48 c7 c7 63 55 1d 85 4c 89 fe 4c 89 f2 4c 89 f9 45 89 e8 31 c0 55 e8 07 36 b0 ff 48 83 c4 08 <0f> 0b e9 fd fe ff ff 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c d4 fe ff
RSP: 0018:ffff8881e8837708 EFLAGS: 00010282
RAX: 0000000000000055 RBX: ffffffff8546c8a0 RCX: a3b0bfbbf6f45b00
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff8881e8825420 R08: ffffffff814e47a1 R09: ffffed103ee25e08
R10: ffffed103ee25e08 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881effd7110
 d_walk+0x2e9/0x570 fs/dcache.c:1307
 do_one_tree fs/dcache.c:1604 [inline]
 shrink_dcache_for_umount+0x8a/0x1b0 fs/dcache.c:1620
 generic_shutdown_super+0x63/0x2a0 fs/super.c:447
 kill_anon_super fs/super.c:1108 [inline]
 kill_litter_super+0x71/0xa0 fs/super.c:1117
 deactivate_locked_super+0xaf/0x100 fs/super.c:335
 deactivate_super+0x1b8/0x280 fs/super.c:366
 cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102
 task_work_run+0x176/0x1a0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xcc2/0x2830 kernel/exit.c:812
 do_group_exit+0x155/0x2b0 kernel/exit.c:910
 get_signal+0x13ec/0x1f00 kernel/signal.c:2745
 do_signal+0x92/0x5d0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x207/0x310 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x449f69
Code: Bad RIP value.
RSP: 002b:00007f3bb7b212f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000004cb4d0 RCX: 0000000000449f69
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000004cb4d8
RBP: 6e656d6572636e69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 766974616c65723d R14: 65646f6e695f726e R15: 00000000004cb4d8
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (10):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-android-5-4-kasan 2021/02/01 05:31 android12-5.4 1e5f5a14faba fc9fd31e .config console log report syz C BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/07/22 03:59 android12-5.4 fe8243e7f1d1 29c3f20f .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/06/24 18:49 android12-5.4 87c05c860576 ec865f6a .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/05/02 08:10 android12-5.4 a50424773496 77e2b668 .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/04/25 06:39 android12-5.4 aa0556d71ff1 17f0b706 .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/04/24 19:07 android12-5.4 aa0556d71ff1 17f0b706 .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/04/15 18:28 android12-5.4 ce6a5172613f c59079a6 .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/03/30 11:16 android12-5.4 1dc47fb418c8 6a81331a .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/03/17 11:26 android12-5.4 160cae0caf16 fdb2bb2c .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
ci2-android-5-4-kasan 2021/02/01 05:17 android12-5.4 1e5f5a14faba fc9fd31e .config console log report info BUG: Dentry still in use [unmount of tmpfs tmpfs]
* Struck through repros no longer work on HEAD.