syzbot


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

Status: closed as dup on 2021/10/28 13:08
Reported-by: syzbot+fa674568322ad3811dac@syzkaller.appspotmail.com
First crash: 463d, last: 463d
Duplicate of (1):
Title Repro Cause bisect Fix bisect Count Last Reported
BUG: Dentry still in use [unmount of ramfs ramfs] C error 3 465d 466d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-54 BUG: Dentry still in use [unmount of devpts devpts] C 11 474d 771d 0/2 upstream: reported C repro on 2020/12/21 14:18
android-5-10 BUG: Dentry still in use [unmount of ext4 loop0] C error 63 426d 464d 0/2 closed as dup on 2021/10/28 13:08

Sample crash report:
BUG: Dentry ffff888119adf770{i=0,n=.index}  still in use (1) [unmount of devpts devpts]
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1316 at fs/dcache.c:1616 umount_check+0x18d/0x1d0 fs/dcache.c:1607
Modules linked in:
CPU: 0 PID: 1316 Comm: syz-executor.1 Tainted: G        W         5.10.75-syzkaller-01082-g234d53d2bb60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:umount_check+0x18d/0x1d0 fs/dcache.c:1607
Code: 8b 0b 49 81 c6 f8 03 00 00 48 c7 c7 40 43 2e 85 4c 89 e6 48 8b 55 d0 4c 89 e1 45 89 f8 31 c0 41 56 e8 ae d9 9e ff 48 83 c4 08 <0f> 0b e9 f1 fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c c9 fe ff
RSP: 0018:ffffc90005c67c68 EFLAGS: 00010282
RAX: 0000000000000057 RBX: ffffffff866730c0 RCX: ea9e27bc433c3400
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc90005c67c98 R08: ffffffff81545368 R09: ffffed103ee095d8
R10: ffffed103ee095d8 R11: 0000000000000000 R12: ffff888119adf770
R13: dffffc0000000000 R14: ffff88810c24e3f8 R15: 0000000000000001
FS:  00005555558d2400(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f25d126e343 CR3: 0000000150cda000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 d_walk+0x309/0x540 fs/dcache.c:1326
 do_one_tree fs/dcache.c:1623 [inline]
 shrink_dcache_for_umount+0x8e/0x1b0 fs/dcache.c:1639
 generic_shutdown_super+0x66/0x2c0 fs/super.c:447
 kill_anon_super fs/super.c:1108 [inline]
 kill_litter_super+0x75/0xa0 fs/super.c:1117
 devpts_kill_sb+0x61/0x70 fs/devpts/inode.c:515
 deactivate_locked_super+0xb0/0x100 fs/super.c:335
 deactivate_super+0xa5/0xd0 fs/super.c:366
 cleanup_mnt+0x45f/0x510 fs/namespace.c:1118
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125
 task_work_run+0x147/0x1b0 kernel/task_work.c:154
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
 exit_to_user_mode_prepare+0xc3/0xe0 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x24/0x40 kernel/entry/common.c:266
 do_syscall_64+0x3d/0x70 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fb6d2042ea7
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:00007ffdf3bcca48 EFLAGS: 00000206
 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fb6d2042ea7
RDX: 00007ffdf3bccb1c RSI: 0000000000000002 RDI: 00007ffdf3bccb10
RBP: 00007ffdf3bccb10 R08: 00000000ffffffff R09: 00007ffdf3bcc8e0
R10: 00005555558d3b83 R11: 0000000000000206 R12: 00007fb6d209b035
R13: 00007ffdf3bcdbd0 R14: 00005555558d3b00 R15: 00007ffdf3bcdc10
---[ end trace 0c697c6dbf6663d5 ]---
VFS: Busy inodes after unmount of devpts. Self-destruct in 5 seconds.  Have a nice day...

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-android-5-10 2021/10/25 03:54 android12-5.10-lts 234d53d2bb60 4f0000ee .config console log report info BUG: Dentry still in use [unmount of devpts devpts]
* Struck through repros no longer work on HEAD.