syzbot


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

Status: closed as dup on 2021/10/28 13:08
Reported-by: syzbot+998a0a55fc5a11ead345@syzkaller.appspotmail.com
First crash: 460d, last: 459d

Cause bisection: failed (bisect log)
Duplicate of (1):
Title Repro Cause bisect Fix bisect Count Last Reported
BUG: Dentry still in use [unmount of ramfs ramfs] C error 3 462d 463d
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 423d 461d 0/2 closed as dup on 2021/10/28 13:08
android-54 BUG: Dentry still in use [unmount of fuse fuse] C 5 460d 748d 0/2 upstream: reported C repro on 2021/01/10 04:39

Sample crash report:
incfs: Can't find or create .index dir in ./file0
BUG: Dentry ffff888119d5abb0{i=0,n=.index}  still in use (1) [unmount of fuse fuse]
------------[ cut here ]------------
WARNING: CPU: 0 PID: 331 at fs/dcache.c:1616 umount_check+0x18d/0x1d0 fs/dcache.c:1607
Modules linked in:
CPU: 0 PID: 331 Comm: syz-executor761 Not tainted 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:ffffc90000b87740 EFLAGS: 00010292
RAX: 0000000000000053 RBX: ffffffff866ce2a0 RCX: 192a07ed2ea85000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc90000b87770 R08: ffffffff81545368 R09: fffff52000170e15
R10: fffff52000170e15 R11: 0000000000000000 R12: ffff888119d5abb0
R13: dffffc0000000000 R14: ffff88811d4943f8 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f217aed3300 CR3: 000000000640f000 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+0x3c/0x70 fs/super.c:1108
 fuse_kill_sb_anon+0x1e8/0x200 fs/fuse/inode.c:1591
 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
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0x70e/0x23a0 kernel/exit.c:813
 do_group_exit+0x16a/0x2d0 kernel/exit.c:910
 get_signal+0x133e/0x1f80 kernel/signal.c:2790
 arch_do_signal+0x8d/0x620 arch/x86/kernel/signal.c:805
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xaa/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: 0033:0x7f8fa125ac89
Code: Unable to access opcode bytes at RIP 0x7f8fa125ac5f.
RSP: 002b:00007f8fa11eb2f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffc RBX: 00007f8fa12e64d0 RCX: 00007f8fa125ac89
RDX: 0000000020000140 RSI: 0000000020000100 RDI: 0000000020000180
RBP: 00007f8fa12b3124 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 00007ffd191b5d8f R14: 6e656d6572636e69 R15: 00007f8fa12e64d8
---[ end trace e486079738835b13 ]---
VF

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-android-5-10 2021/10/26 05:50 android12-5.10-lts 234d53d2bb60 c1132b49 .config console log report syz C BUG: Dentry still in use [unmount of fuse fuse]
ci2-android-5-10 2021/10/24 15:13 android12-5.10-lts 234d53d2bb60 282f03fb .config console log report syz C BUG: Dentry still in use [unmount of fuse fuse]
ci2-android-5-10 2021/10/24 14:07 android12-5.10-lts 234d53d2bb60 282f03fb .config console log report info BUG: Dentry still in use [unmount of fuse fuse]
* Struck through repros no longer work on HEAD.