[v6.1] BUG: unable to handle kernel NULL pointer dereference in filemap_read_folio

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fdb6fcb41cc7 Linux 6.1.176
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17f55b76580000
kernel config: https://syzkaller.appspot.com/x/.config?x=acfbe65fbce84c0c
dashboard link: https://syzkaller.appspot.com/bug?extid=b95765d1ee2f94925081
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1609e67fe610/disk-fdb6fcb4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7c9914a35256/vmlinux-fdb6fcb4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/401dd54d7ec6/bzImage-fdb6fcb4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b95765...@syzkaller.appspotmail.com

ntfs: volume version 3.1.
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 7cf8d067 P4D 7cf8d067 PUD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 11906 Comm: syz.2.3511 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90003a277b8 EFLAGS: 00010283
RAX: ffffffff81aca885 RBX: ffffea00013631c0 RCX: 0000000000080000
RDX: ffffc900133b9000 RSI: ffffea00013631c0 RDI: 0000000000000000
RBP: ffffc90003a27878 R08: ffffea00013631c7 R09: 1ffffd400026c638
R10: dffffc0000000000 R11: fffff9400026c639 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffffd400026c639 R15: 1ffff92000744efc
FS: 00007f1cd50196c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000070818000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
filemap_read_folio+0x164/0x7a0 mm/filemap.c:2490
do_read_cache_folio+0x29e/0x790 mm/filemap.c:3659
do_read_cache_page+0x32/0x230 mm/filemap.c:3701
read_mapping_page include/linux/pagemap.h:793 [inline]
ntfs_map_page fs/ntfs/aops.h:75 [inline]
ntfs_check_logfile+0x28f/0x25c0 fs/ntfs/logfile.c:532
load_and_check_logfile+0x6f/0xd0 fs/ntfs/super.c:1215
load_system_files+0x2ecc/0x44f0 fs/ntfs/super.c:1941
ntfs_fill_super+0x187c/0x2ac0 fs/ntfs/super.c:2892
mount_bdev+0x28a/0x3c0 fs/super.c:1443
legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
vfs_get_tree+0x88/0x270 fs/super.c:1573
do_new_mount+0x247/0xa40 fs/namespace.c:3078
do_mount fs/namespace.c:3421 [inline]
__do_sys_mount fs/namespace.c:3629 [inline]
__se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606
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: 0033:0x7f1cd419e0ca
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f1cd5018e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1cd5018ee0 RCX: 00007f1cd419e0ca
RDX: 0000200000000100 RSI: 000020000001ecc0 RDI: 00007f1cd5018ea0
RBP: 0000200000000100 R08: 00007f1cd5018ee0 R09: 0000000000008000
R10: 0000000000008000 R11: 0000000000000246 R12: 000020000001ecc0
R13: 00007f1cd5018ea0 R14: 000000000001ec7e R15: 0000200000000200
</TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90003a277b8 EFLAGS: 00010283
RAX: ffffffff81aca885 RBX: ffffea00013631c0 RCX: 0000000000080000
RDX: ffffc900133b9000 RSI: ffffea00013631c0 RDI: 0000000000000000
RBP: ffffc90003a27878 R08: ffffea00013631c7 R09: 1ffffd400026c638
R10: dffffc0000000000 R11: fffff9400026c639 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffffd400026c639 R15: 1ffff92000744efc
FS: 00007f1cd50196c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000070818000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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