syzbot


BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop0]

Status: upstream: reported C repro on 2020/12/12 22:33
Reported-by: syzbot+ca0da893506cdeb55232@syzkaller.appspotmail.com
First crash: 1469d, last: 1189d
Fix bisection: failed (error log, bisect log)
  
Fix bisection attempts (9)
Created Duration User Patch Repo Result
2021/10/19 09:53 15m bisect fix linux-4.19.y error job log
2021/09/19 09:27 26m bisect fix linux-4.19.y OK (0) job log log
2021/08/20 08:10 28m bisect fix linux-4.19.y OK (0) job log log
2021/07/21 07:09 23m bisect fix linux-4.19.y OK (0) job log log
2021/06/03 23:45 27m bisect fix linux-4.19.y OK (0) job log log
2021/05/04 23:23 21m bisect fix linux-4.19.y OK (0) job log log
2021/04/04 22:52 31m bisect fix linux-4.19.y OK (0) job log log
2021/03/05 21:45 22m bisect fix linux-4.19.y OK (0) job log log
2021/01/11 22:32 23m bisect fix linux-4.19.y OK (0) job log log

Sample crash report:
RAX: ffffffffffffffda RBX: 00007fff3559e0d0 RCX: 000000000044f23a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fff3559e090
RBP: 00007fff3559e090 R08: 00007fff3559e0d0 R09: 002c72747461785f
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000020000248
R13: 0000000000000005 R14: 0000000000000006 R15: 0000000000000003
BUG: Dentry 0000000097ce868b{i=0,n=/}  still in use (-128) [unmount of erofs loop0]
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8135 at fs/dcache.c:1518 umount_check fs/dcache.c:1518 [inline]
WARNING: CPU: 0 PID: 8135 at fs/dcache.c:1518 umount_check.cold+0xf2/0x116 fs/dcache.c:1499
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 8135 Comm: syz-executor786 Not tainted 4.19.172-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 __warn.cold+0x20/0x5a kernel/panic.c:541
 report_bug+0x262/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:umount_check fs/dcache.c:1518 [inline]
RIP: 0010:umount_check.cold+0xf2/0x116 fs/dcache.c:1499
Code: f9 4d 89 f1 45 89 e0 48 89 e9 41 55 4c 89 fa 48 89 ee 48 c7 c7 c0 a2 74 88 e8 44 f0 fe ff 48 c7 c7 c0 a1 74 88 e8 38 f0 fe ff <0f> 0b 58 e9 c0 bf b6 f9 e8 2c 6b a6 f9 e9 22 ff ff ff 48 89 df e8
RSP: 0018:ffff8880957bfa98 EFLAGS: 00010286
RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814de0d1 RDI: ffffed1012af7f45
RBP: ffff88808e5b0300 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 00000000ffffff80
R13: ffff888094db4710 R14: ffffffff893f58a0 R15: 0000000000000000
 d_walk+0x196/0x990 fs/dcache.c:1253
 do_one_tree fs/dcache.c:1525 [inline]
 shrink_dcache_for_umount+0x87/0x330 fs/dcache.c:1541
 generic_shutdown_super+0x68/0x370 fs/super.c:441
 kill_block_super+0x97/0xf0 fs/super.c:1185
 deactivate_locked_super+0x94/0x160 fs/super.c:329
 mount_bdev+0x373/0x3b0 fs/super.c:1160
 erofs_mount+0x8c/0xc0 drivers/staging/erofs/super.c:512
 mount_fs+0xa3/0x310 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x113c/0x2f10 fs/namespace.c:2799
 ksys_mount+0xcf/0x130 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44f23a
Code: 48 c7 c2 c4 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 58 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c4 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff3559e078 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff3559e0d0 RCX: 000000000044f23a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fff3559e090
RBP: 00007fff3559e090 R08: 00007fff3559e0d0 R09: 002c72747461785f
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000020000248
R13: 0000000000000005 R14: 0000000000000006 R15: 0000000000000003
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/02/03 21:45 linux-4.19.y 811218eceeaa 624dad51 .config console log report syz C ci2-linux-4-19 BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop0]
2020/12/12 22:32 linux-4.19.y 13d2ce42de8c bca53db9 .config console log report syz C ci2-linux-4-19
2021/06/21 07:09 linux-4.19.y eb575cd5d7f6 aba2b2fb .config console log report info ci2-linux-4-19 BUG: Dentry ADDR{i=0,n=/} still in use (-128) [unmount of erofs loop0]
* Struck through repros no longer work on HEAD.