syzbot


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

Status: upstream: reported C repro on 2021/01/10 04:39
Reported-by: syzbot+8683b7c75512cf582f3b@syzkaller.appspotmail.com
First crash: 689d, last: 401d
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 364d 403d 0/2 closed as dup on 2021/10/28 13:08
android-5-10 BUG: Dentry still in use [unmount of fuse fuse] C error 3 400d 402d 0/2 closed as dup on 2021/10/28 13:08

Sample crash report:
incfs: Can't find or create .index dir in ./file0
BUG: Dentry ffff8881e7a94880{i=0,n=.index}  still in use (1) [unmount of fuse fuse]
------------[ cut here ]------------
WARNING: CPU: 1 PID: 302 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Modules linked in:
CPU: 1 PID: 302 Comm: syz-executor141 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:ffff8881de0d78e0 EFLAGS: 00010292
RAX: 0000000000000053 RBX: ffffffff85dde460 RCX: 8be02855dff58e00
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff8881de070420 R08: ffffffff814b2a4c R09: ffffed103bc1aed5
R10: ffffed103bc1aed5 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881e7a94880
FS:  00007f6894398700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f689445d2f8 CR3: 0000000005c0e000 CR4: 00000000003406e0
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
 fuse_kill_sb_anon+0x16d/0x210 fs/fuse/inode.c:1378
 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
 get_signal+0x150f/0x1e00 kernel/signal.c:2745
 do_signal+0x3b/0x580 arch/x86/kernel/signal.c:809
 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: 0033:0x7f6894407c89
Code: Bad RIP value.
RSP: 002b:00007f68943982f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffffc RBX: 00007f68944934d0 RCX: 00007f6894407c89
RDX: 0000000020000140 RSI: 0000000020000100 RDI: 0000000020000180
RBP: 00007f6894460124 R08: 0000000000000000 R09: 0000000000000000
R10: 0000

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-android-5-4-kasan 2021/10/25 03:46 android12-5.4 eb4a5a5dbd5b 4f0000ee .config log report syz C BUG: Dentry still in use [unmount of fuse fuse]
ci2-android-5-4-kasan 2021/01/10 04:39 android12-5.4 47494776db44 2c1f2513 .config log report syz C
ci2-android-5-4-kasan 2021/09/22 13:19 android12-5.4 546305780d82 169724fe .config log report info BUG: Dentry still in use [unmount of fuse fuse]
ci2-android-5-4-kasan 2021/08/01 22:42 android12-5.4 e7e1f9adf836 6c236867 .config log report info BUG: Dentry still in use [unmount of fuse fuse]
ci2-android-5-4-kasan 2021/05/19 01:24 android12-5.4 abedbe9da982 a343ba6b .config log report info BUG: Dentry still in use [unmount of fuse fuse]
* Struck through repros no longer work on HEAD.