[Android 6.1] BUG: corrupted list in __dentry_kill (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 478ca7133d0e ANDROID: dm-bow: ignore discard in CHECKPOINT..
git tree: android14-6.1
console output: https://syzkaller.appspot.com/x/log.txt?x=11045644580000
kernel config: https://syzkaller.appspot.com/x/.config?x=19de17fcb07fab22
dashboard link: https://syzkaller.appspot.com/bug?extid=b303d032edd8f655572c
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1646445a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1787e45a580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/78d0e2d9baef/disk-478ca713.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/11934bafcae8/vmlinux-478ca713.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fff4f144061e/bzImage-478ca713.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b303d0...@syzkaller.appspotmail.com

RDX: 0000200000000080 RSI: 00002000000000c0 RDI: 0000000000000000
RBP: 00007f5d12208c1f R08: 0000200000000340 R09: 0000000000000000
R10: 0000000001004040 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5d12415fac R14: 00007f5d12415fa0 R15: 00007f5d12415fa0
</TASK>
---[ end trace 0000000000000000 ]---
list_del corruption. prev->next should be ffff888123157a20, but was ffff888111588c40. (prev=ffff888123159800)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 432 Comm: syz.1.30 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__list_del_entry_valid+0x10f/0x130 lib/list_debug.c:59
Code: e8 2e 4a 88 02 0f 0b 48 c7 c7 00 76 ca 85 48 89 de e8 1d 4a 88 02 0f 0b 48 c7 c7 60 76 ca 85 48 89 de 4c 89 f9 e8 09 4a 88 02 <0f> 0b 48 c7 c7 e0 76 ca 85 48 89 de 4c 89 f1 e8 f5 49 88 02 0f 0b
RSP: 0018:ffffc90000e87378 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff888123157a20 RCX: 2869bba1fbe78300
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc90000e87398 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001d0dc0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888111588c40 R15: ffff888123159800
FS: 000055557c06e500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c006ff7000 CR3: 000000012ebe7000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__list_del_entry include/linux/list.h:134 [inline]
dentry_unlist fs/dcache.c:554 [inline]
__dentry_kill+0x25d/0x670 fs/dcache.c:607
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x42/0x80 fs/dcache.c:918
path_put+0x39/0x60 fs/namei.c:560
dentry_release+0x4f/0xa0 fs/incfs/vfs.c:1614
__dentry_kill+0x4d4/0x670 fs/dcache.c:616
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x42/0x80 fs/dcache.c:918
path_put+0x39/0x60 fs/namei.c:560
dentry_release+0x4f/0xa0 fs/incfs/vfs.c:1614
__dentry_kill+0x4d4/0x670 fs/dcache.c:616
dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
dput+0x42/0x80 fs/dcache.c:918
ovl_workdir_create+0x2aa/0x6d0 fs/overlayfs/super.c:812
ovl_make_workdir fs/overlayfs/super.c:1410 [inline]
ovl_get_workdir+0x3bd/0x14e0 fs/overlayfs/super.c:1560
ovl_fill_super+0x18c2/0x2a20 fs/overlayfs/super.c:2116
mount_nodev+0x6a/0x100 fs/super.c:1491
ovl_mount+0x2c/0x40 fs/overlayfs/super.c:2206
legacy_get_tree+0xfe/0x1a0 fs/fs_context.c:632
vfs_get_tree+0x9a/0x270 fs/super.c:1575
do_new_mount+0x25a/0xa20 fs/namespace.c:3078
path_mount+0x659/0xfc0 fs/namespace.c:3408
do_mount fs/namespace.c:3421 [inline]
__do_sys_mount fs/namespace.c:3629 [inline]
__se_sys_mount+0x320/0x390 fs/namespace.c:3606
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3606
x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5d1219aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc11a72f38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5d12415fa0 RCX: 00007f5d1219aeb9
RDX: 0000200000000080 RSI: 00002000000000c0 RDI: 0000000000000000
RBP: 00007f5d12208c1f R08: 0000200000000340 R09: 0000000000000000
R10: 0000000001004040 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5d12415fac R14: 00007f5d12415fa0 R15: 00007f5d12415fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid+0x10f/0x130 lib/list_debug.c:59
Code: e8 2e 4a 88 02 0f 0b 48 c7 c7 00 76 ca 85 48 89 de e8 1d 4a 88 02 0f 0b 48 c7 c7 60 76 ca 85 48 89 de 4c 89 f9 e8 09 4a 88 02 <0f> 0b 48 c7 c7 e0 76 ca 85 48 89 de 4c 89 f1 e8 f5 49 88 02 0f 0b
RSP: 0018:ffffc90000e87378 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff888123157a20 RCX: 2869bba1fbe78300
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc90000e87398 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001d0dc0 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888111588c40 R15: ffff888123159800
FS: 000055557c06e500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c006ff7000 CR3: 000000012ebe7000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

Bug presence analysis results: the bug reproduces only on Android 6.1.

syzbot has run the reproducer on other relevant kernel trees and got
the following results:

android14-6.1 (commit 478ca7133d0e) on 2026/02/01:
BUG: corrupted list in __dentry_kill
Report: https://syzkaller.appspot.com/x/report.txt?x=1403bc5a580000

lts (commit e50b81c50fcb) on 2026/02/01:
Didn't crash.

upstream (commit 162b42445b58) on 2026/02/01:
Didn't crash.

More details can be found at:
https://syzkaller.appspot.com/bug?extid=b303d032edd8f655572c