syzbot


BUG: Dentry still in use [unmount of 9p 9p]

Status: upstream: reported C repro on 2021/01/31 03:12
Reported-by: syzbot+6e9fc6ed2622084c544b@syzkaller.appspotmail.com
First crash: 674d, last: 409d
similar bugs (2):
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 370d 408d 0/2 closed as dup on 2021/10/28 13:08
android-5-10 BUG: Dentry still in use [unmount of 9p 9p] C error 3 407d 409d 0/2 closed as dup on 2021/10/28 12:58

Sample crash report:
incfs: Can't find or create .index dir in ./file0
BUG: Dentry ffff8881e6a7caa0{i=0,n=.index}  still in use (1) [unmount of 9p 9p]
------------[ cut here ]------------
WARNING: CPU: 0 PID: 299 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Modules linked in:
CPU: 0 PID: 299 Comm: syz-executor275 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:ffff8881de08fb58 EFLAGS: 00010282
RAX: 000000000000004f RBX: ffffffff85de78e0 RCX: 27c1f4af29334600
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff8881de25a420 R08: ffffffff814b2a4c R09: ffffed103edc9608
R10: ffffed103edc9608 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881e6a7caa0
FS:  00005555562de300(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3bb8382290 CR3: 00000001edc66000 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_anon_super+0x36/0x60 fs/super.c:1108
 v9fs_kill_super+0x48/0x90 fs/9p/vfs_super.c:219
 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
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xc0a/0x2aa0 kernel/exit.c:812
 do_group_exit+0x15c/0x2c0 kernel/exit.c:910
 __do_sys_exit_group+0x13/0x20 kernel/exit.c:921
 __se_sys_exit_group+0x10/0x10 kernel/exit.c:919
 __x64_sys_exit_group+0x37/0x40 kernel/exit.c:919
 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f3bb830c9a9
Code: Bad RIP value.
RSP: 002b:00007ffddaf25bd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f3bb83813f0 RCX: 00007f3bb830c9a9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffffffffffc0 R09: 00007f3bb837be40
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3bb83813f0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
---[ end trace eedf99dc52fe48f0 ]---
VFS: Busy inodes after unmount of 9p. Self-destruct in 5 seconds.  Have a nice day...
9pnet: Found fid 0 not clunked
9pnet: Found fid 1 not clunked

Crashes (11):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-android-5-4-kasan 2021/10/23 11:24 android12-5.4 eb4a5a5dbd5b 282f03fb .config log report syz C BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/03/07 07:00 android12-5.4 1bd00b1a96b5 e4b4d570 .config log report syz C BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/01/31 03:30 android12-5.4 1e5f5a14faba fc9fd31e .config log report syz C BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/10/16 06:45 android12-5.4 73e6d86c30ee 0c5d9412 .config log report info BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/10/06 16:15 android12-5.4 1e429b8f9eb9 0a63fd36 .config log report info BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/05/15 07:30 android12-5.4 7c784dd70490 8bdd5343 .config log report info BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/04/12 22:11 android12-5.4 3c5dbcf40ba8 6a81331a .config log report info BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/03/28 01:19 android12-5.4 7af03784d889 a8529b82 .config log report info BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/03/20 12:46 android12-5.4 c2f379e025e4 e45f5621 .config log report info BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/02/24 23:37 android12-5.4 7ba24942b70e fcc6d71b .config log report info BUG: Dentry still in use [unmount of 9p 9p]
ci2-android-5-4-kasan 2021/01/31 03:12 android12-5.4 1e5f5a14faba fc9fd31e .config log report info BUG: Dentry still in use [unmount of 9p 9p]
* Struck through repros no longer work on HEAD.