[v5.15] BUG: unable to handle kernel paging request in udf_statfs

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 91d48252ad4b Linux 5.15.202
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16dfca02580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=464f8ed46b24690edf39
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/74e75dfcb812/disk-91d48252.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bfa72aab00f2/vmlinux-91d48252.xz
kernel image: https://storage.googleapis.com/syzbot-assets/47ea72d1c7dc/bzImage-91d48252.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+464f8e...@syzkaller.appspotmail.com

BUG: unable to handle page fault for address: ffffed101829d363
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 23ffef067 P4D 23ffef067 PUD 13fff6067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 28911 Comm: syz.2.2908 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:udf_statfs+0xb87/0x1040 fs/udf/super.c:2444
Code: 08 48 89 df e8 1a f0 f4 fe 4c 89 74 24 18 4c 89 33 4d 85 ff 74 72 e8 28 e4 af fe 49 8d 7f 20 4d 8d 77 23 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 80 02 00 00 4c 89 f0 48 c1 e8 03 42 0f
RSP: 0018:ffffc90003c7f820 EFLAGS: 00010a06
RAX: 1ffff1101829d363 RBX: ffffc90003c7fa60 RCX: 0000000000080000
RDX: ffffc90017001000 RSI: 000000000000da10 RDI: ffff8880c14e9b18
RBP: ffffc90003c7f9a8 R08: ffff888067c43b80 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: ffffc90003c7fa40 R14: ffff8880c14e9b1b R15: ffff8880c14e9af8
FS: 00007f91c4ec36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed101829d363 CR3: 0000000019de0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000000000b2
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
statfs_by_dentry fs/statfs.c:66 [inline]
vfs_statfs+0x13d/0x2c0 fs/statfs.c:90
ovl_check_namelen fs/overlayfs/super.c:922 [inline]
ovl_get_upper+0x1c0/0x600 fs/overlayfs/super.c:1214
ovl_fill_super+0x160c/0x2a30 fs/overlayfs/super.c:2068
mount_nodev+0x52/0xe0 fs/super.c:1446
legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
vfs_get_tree+0x88/0x270 fs/super.c:1530
do_new_mount+0x24a/0xa40 fs/namespace.c:3034
do_mount fs/namespace.c:3377 [inline]
__do_sys_mount fs/namespace.c:3585 [inline]
__se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f91c6c8a799
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:00007f91c4ec3028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f91c6f04090 RCX: 00007f91c6c8a799
RDX: 0000200000000b80 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007f91c6d20bd9 R08: 0000200000000200 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f91c6f04128 R14: 00007f91c6f04090 R15: 00007ffcc5fb6ab8
</TASK>
Modules linked in:
CR2: ffffed101829d363
---[ end trace bfae8e8da3c6f01e ]---
RIP: 0010:udf_statfs+0xb87/0x1040 fs/udf/super.c:2444
Code: 08 48 89 df e8 1a f0 f4 fe 4c 89 74 24 18 4c 89 33 4d 85 ff 74 72 e8 28 e4 af fe 49 8d 7f 20 4d 8d 77 23 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 80 02 00 00 4c 89 f0 48 c1 e8 03 42 0f
RSP: 0018:ffffc90003c7f820 EFLAGS: 00010a06
RAX: 1ffff1101829d363 RBX: ffffc90003c7fa60 RCX: 0000000000080000
RDX: ffffc90017001000 RSI: 000000000000da10 RDI: ffff8880c14e9b18
RBP: ffffc90003c7f9a8 R08: ffff888067c43b80 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: ffffc90003c7fa40 R14: ffff8880c14e9b1b R15: ffff8880c14e9af8
FS: 00007f91c4ec36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffed101829d363 CR3: 0000000019de0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000000000b2
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 08 48 89 or %cl,-0x77(%rax)
3: df e8 fucomip %st(0),%st
5: 1a f0 sbb %al,%dh
7: f4 hlt
8: fe 4c 89 74 decb 0x74(%rcx,%rcx,4)
c: 24 18 and $0x18,%al
e: 4c 89 33 mov %r14,(%rbx)
11: 4d 85 ff test %r15,%r15
14: 74 72 je 0x88
16: e8 28 e4 af fe call 0xfeafe443
1b: 49 8d 7f 20 lea 0x20(%r15),%rdi
1f: 4d 8d 77 23 lea 0x23(%r15),%r14
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 80 02 00 00 jne 0x2b7
37: 4c 89 f0 mov %r14,%rax
3a: 48 c1 e8 03 shr $0x3,%rax
3e: 42 rex.X
3f: 0f .byte 0xf


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup