[Android 6.1] general protection fault in ovl_lookup_single (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d73749230104 ANDROID: gki_defconfig: Enable Nintendo Force..
git tree: android14-6.1
console output: https://syzkaller.appspot.com/x/log.txt?x=10a45e7a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=69841d35933a4e41
dashboard link: https://syzkaller.appspot.com/bug?extid=eff0568b3b84daefa9d2
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=1466c72e580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14f41b7e580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/290cce68a7b0/disk-d7374923.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7c396c49862a/vmlinux-d7374923.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0ed52005907e/bzImage-d7374923.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+eff056...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:ovl_lookup_positive_unlocked fs/overlayfs/namei.c:209 [inline]
RIP: 0010:ovl_lookup_single+0x15e/0x9c0 fs/overlayfs/namei.c:233
Code: e8 47 1c 5e ff 49 bf 00 00 00 00 00 fc ff df e9 4b 04 00 00 44 88 6c 24 10 4d 89 f5 49 c1 ed 03 49 bf 00 00 00 00 00 fc ff df <43> 0f b6 44 3d 00 84 c0 0f 85 61 06 00 00 4d 89 f7 45 8b 36 44 89
RSP: 0018:ffffc900009a7980 EFLAGS: 00010203
RAX: 0000000000000016 RBX: ffffc900009a7bd8 RCX: 723449db75d93500
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: ffffc900009a7a50 R08: ffff888122f195e7 R09: 1ffff110245e32bc
R10: dffffc0000000000 R11: ffffed10245e32bd R12: 1ffff92000134f7b
R13: 0000000000000002 R14: 0000000000000016 R15: dffffc0000000000
FS: 00007fc0f3e096c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc0f3dc6ff8 CR3: 000000012f50b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ovl_lookup_layer+0x355/0x420 fs/overlayfs/namei.c:320
ovl_lookup+0x728/0x1980 fs/overlayfs/namei.c:923
lookup_one_qstr_excl+0x125/0x270 fs/namei.c:1612
filename_create+0x235/0x470 fs/namei.c:3884
do_mkdirat+0x5c/0x4c0 fs/namei.c:4128
__do_sys_mkdirat fs/namei.c:4153 [inline]
__se_sys_mkdirat fs/namei.c:4151 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4151
x64_sys_call+0x73d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
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: 0033:0x7fc0f2f9ce59
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:00007fc0f3e09028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fc0f3215fa0 RCX: 00007fc0f2f9ce59
RDX: 0000000000000000 RSI: 0000200000002000 RDI: ffffffffffffff9c
RBP: 00007fc0f3032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc0f3216038 R14: 00007fc0f3215fa0 R15: 00007fff06d384a8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ovl_lookup_positive_unlocked fs/overlayfs/namei.c:209 [inline]
RIP: 0010:ovl_lookup_single+0x15e/0x9c0 fs/overlayfs/namei.c:233
Code: e8 47 1c 5e ff 49 bf 00 00 00 00 00 fc ff df e9 4b 04 00 00 44 88 6c 24 10 4d 89 f5 49 c1 ed 03 49 bf 00 00 00 00 00 fc ff df <43> 0f b6 44 3d 00 84 c0 0f 85 61 06 00 00 4d 89 f7 45 8b 36 44 89
RSP: 0018:ffffc900009a7980 EFLAGS: 00010203
RAX: 0000000000000016 RBX: ffffc900009a7bd8 RCX: 723449db75d93500
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: ffffc900009a7a50 R08: ffff888122f195e7 R09: 1ffff110245e32bc
R10: dffffc0000000000 R11: ffffed10245e32bd R12: 1ffff92000134f7b
R13: 0000000000000002 R14: 0000000000000016 R15: dffffc0000000000
FS: 00007fc0f3e096c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc0f3dc6ff8 CR3: 000000012f50b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: e8 47 1c 5e ff call 0xff5e1c4c
5: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15
c: fc ff df
f: e9 4b 04 00 00 jmp 0x45f
14: 44 88 6c 24 10 mov %r13b,0x10(%rsp)
19: 4d 89 f5 mov %r14,%r13
1c: 49 c1 ed 03 shr $0x3,%r13
20: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15
27: fc ff df
* 2a: 43 0f b6 44 3d 00 movzbl 0x0(%r13,%r15,1),%eax <-- trapping instruction
30: 84 c0 test %al,%al
32: 0f 85 61 06 00 00 jne 0x699
38: 4d 89 f7 mov %r14,%r15
3b: 45 8b 36 mov (%r14),%r14d
3e: 44 rex.R
3f: 89 .byte 0x89


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