syzbot


BUG: Dentry still in use [unmount of vfat loop2]

Status: auto-closed as invalid on 2022/02/21 04:30
Reported-by: syzbot+5c5bd366c00018973545@syzkaller.appspotmail.com
First crash: 1069d, last: 948d
Similar bugs (3)
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 910d 949d 0/2 closed as dup on 2021/10/28 13:08
android-5-10 BUG: Dentry still in use in unmount C done 1184 826d 839d 2/2 fixed on 2022/02/25 03:20
android-54 BUG: Dentry still in use [unmount of ramfs ramfs] C 476 845d 1167d 0/2 auto-obsoleted due to no activity on 2023/04/21 02:49

Sample crash report:
BUG: Dentry ffff88819d00f880{i=0,n=.index}  still in use (1) [unmount of vfat loop2]
------------[ cut here ]------------
WARNING: CPU: 0 PID: 313 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Modules linked in:
CPU: 0 PID: 313 Comm: syz-executor.2 Not tainted 5.4.147-syzkaller-00036-geb4a5a5dbd5b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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 e0 14 c9 84 4c 89 fe 4c 89 f2 4c 89 f9 45 89 e8 31 c0 55 e8 b7 0e b3 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:ffff8881a92dfcc0 EFLAGS: 00010296
RAX: 0000000000000054 RBX: ffffffff85dc6240 RCX: 9e4e547ed8397100
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff8881e134f420 R08: ffffffff814b2a4c R09: ffffed103edc9608
R10: ffffed103edc9608 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88819d00f880
FS:  0000555555ce8400(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555cf1b38 CR3: 00000001a9249000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 d_walk+0x2d9/0x540 fs/dcache.c:1307
 do_one_tree fs/dcache.c:1604 [inline]
 shrink_dcache_for_umount+0x8a/0x1a0 fs/dcache.c:1620
 generic_shutdown_super+0x63/0x2a0 fs/super.c:447
 kill_block_super+0x79/0xd0 fs/super.c:1444
 deactivate_locked_super+0xaf/0x100 fs/super.c:335
 deactivate_super+0x168/0x210 fs/super.c:366
 cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102
 task_work_run+0x186/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
 prepare_exit_to_usermode+0x2b0/0x310 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fd68e9b9ea7
Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd64e8bfb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fd68e9b9ea7
RDX: 00007ffd64e8c08a RSI: 0000000000000002 RDI: 00007ffd64e8c080
RBP: 00007ffd64e8c080 R08: 00000000ffffffff R09: 00007ffd64e8be50
R10: 0000555555ce9b83 R11: 0000000000000246 R12: 00007fd68ea12035
R13: 00007ffd64e8d140 R14: 0000555555ce9b00 R15: 00007ffd64e8d180
---[ end trace 9088ab2f18520e55 ]---
VFS: Busy inodes after unmount of loop2. Self-destruct in 5 seconds.  Have a nice day...

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/10/24 04:29 android12-5.4 eb4a5a5dbd5b 282f03fb .config console log report info ci2-android-5-4-kasan BUG: Dentry still in use [unmount of vfat loop2]
2021/08/08 17:10 android12-5.4 306607c78507 6972b106 .config console log report info ci2-android-5-4-kasan BUG: Dentry still in use [unmount of vfat loop2]
2021/07/06 13:28 android12-5.4 eaef435f4357 6c4484eb .config console log report info ci2-android-5-4-kasan BUG: Dentry still in use [unmount of vfat loop2]
2021/07/04 21:13 android12-5.4 eaef435f4357 55aa55c2 .config console log report info ci2-android-5-4-kasan BUG: Dentry still in use [unmount of vfat loop2]
2021/06/25 06:12 android12-5.4 47fe7966921f 0edbbe31 .config console log report info ci2-android-5-4-kasan BUG: Dentry still in use [unmount of vfat loop2]
* Struck through repros no longer work on HEAD.