BUG: corrupted list in __dentry_kill

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 6dd0e326 Linux 4.19.115
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=158e84d7e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=75bfa32b46e7b6cf
dashboard link: https://syzkaller.appspot.com/bug?extid=dc38846dda0d1a9571cc
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+dc3884...@syzkaller.appspotmail.com

list_del corruption. next->prev should be ffff88805f8b5290, but was 0000000000000000
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:54!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 28380 Comm: systemd-udevd Not tainted 4.19.115-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__list_del_entry_valid.cold+0x48/0x55 lib/list_debug.c:54
Code: e8 5b 6c fc fd 0f 0b 4c 89 e2 48 89 ee 48 c7 c7 80 ff aa 87 e8 47 6c fc fd 0f 0b 48 89 ee 48 c7 c7 40 00 ab 87 e8 36 6c fc fd <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 41 54 55 53 48 89 fb 48 c7
RSP: 0018:ffff88820dff7c98 EFLAGS: 00010286
RAX: 0000000000000054 RBX: ffff8880a98d0c60 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8152d3a1 RDI: ffffed1041bfef85
RBP: ffff88805f8b5290 R08: 0000000000000054 R09: ffffed1015ce5079
R10: ffffed1015ce5078 R11: ffff8880ae7283c7 R12: ffff88804baf7d50
R13: ffff8880008039b0 R14: ffff88805f8b5260 R15: 0000000000000000
FS: 00007f5e570da8c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055df6998b928 CR3: 00000000a4414000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__list_del_entry include/linux/list.h:117 [inline]
dentry_unlist fs/dcache.c:509 [inline]
__dentry_kill+0x1f0/0x5d0 fs/dcache.c:562
dentry_kill+0xc4/0x520 fs/dcache.c:685
dput+0x568/0x650 fs/dcache.c:846
do_renameat2+0xac2/0xbd0 fs/namei.c:4633
__do_sys_rename fs/namei.c:4675 [inline]
__se_sys_rename fs/namei.c:4673 [inline]
__x64_sys_rename+0x5d/0x80 fs/namei.c:4673
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f5e55ed6d47
Code: 75 12 48 89 df e8 19 84 07 00 85 c0 0f 95 c0 0f b6 c0 f7 d8 5b c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 52 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 21 41 33 00 f7 d8 64 89 01 48
RSP: 002b:00007ffca722be18 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 000055df6989dc10 RCX: 00007f5e55ed6d47
RDX: 0000000000000000 RSI: 00007ffca722be20 RDI: 000055df6988fdf0
RBP: 00007ffca722bee0 R08: 000055df6989d1e0 R09: 000055df6989d100
R10: 00007f5e570da8c0 R11: 0000000000000246 R12: 00007ffca722be20
R13: 0000000000000001 R14: 000055df687ae6cb R15: 0000000000000000
Modules linked in:
---[ end trace c87361aad775ded6 ]---
RIP: 0010:__list_del_entry_valid.cold+0x48/0x55 lib/list_debug.c:54
Code: e8 5b 6c fc fd 0f 0b 4c 89 e2 48 89 ee 48 c7 c7 80 ff aa 87 e8 47 6c fc fd 0f 0b 48 89 ee 48 c7 c7 40 00 ab 87 e8 36 6c fc fd <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 41 54 55 53 48 89 fb 48 c7
RSP: 0018:ffff88820dff7c98 EFLAGS: 00010286
RAX: 0000000000000054 RBX: ffff8880a98d0c60 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8152d3a1 RDI: ffffed1041bfef85
RBP: ffff88805f8b5290 R08: 0000000000000054 R09: ffffed1015ce5079
R10: ffffed1015ce5078 R11: ffff8880ae7283c7 R12: ffff88804baf7d50
R13: ffff8880008039b0 R14: ffff88805f8b5260 R15: 0000000000000000
FS: 00007f5e570da8c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055df6998b928 CR3: 00000000a4414000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.