[syzbot] [erofs?] [mm?] BUG: unable to handle kernel NULL pointer dereference in filemap_read_folio (3)

[syzbot <syzbot+001306cd9c92ce0df23f@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    a430d95c5efa Merge tag 'lsm-pr-20240911' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=118e68a9980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1653f803fffa3848
dashboard link: https://syzkaller.appspot.com/bug?extid=001306cd9c92ce0df23f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1452dc07980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=158e68a9980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-a430d95c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/66a65abf87c4/vmlinux-a430d95c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/09c88015f9aa/bzImage-a430d95c.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/00e0bb849690/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+001306cd9c92ce0df23f@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 256
vfat: Unknown parameter 's'
./file1: Can't lookup blockdev
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 127b0067 P4D 127b0067 PUD 127b1067 PMD 0 
Oops: Oops: 0010 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5096 Comm: syz-executor418 Not tainted 6.11.0-syzkaller-02574-ga430d95c5efa #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90002d7f9f8 EFLAGS: 00010293
RAX: ffffffff81cb4ee0 RBX: 0000000000000000 RCX: ffff88801e428000
RDX: 0000000000000000 RSI: ffffea00004bfec0 RDI: 0000000000000000
RBP: ffffc90002d7fac0 R08: ffffea00004bfec7 R09: 1ffffd4000097fd8
R10: dffffc0000000000 R11: 0000000000000000 R12: ffffea00004bfec0
R13: 1ffffd4000097fd9 R14: 0000000000000000 R15: ffffea00004bfec8
FS:  000055558992f380(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000011be2000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 filemap_read_folio+0x1a0/0x790 mm/filemap.c:2355
 do_read_cache_folio+0x134/0x820 mm/filemap.c:3796
 read_mapping_folio include/linux/pagemap.h:915 [inline]
 erofs_bread+0x499/0xd40 fs/erofs/data.c:41
 erofs_read_superblock fs/erofs/super.c:277 [inline]
 erofs_fc_fill_super+0x345/0x1770 fs/erofs/super.c:621
 vfs_get_super fs/super.c:1280 [inline]
 get_tree_nodev+0xb7/0x140 fs/super.c:1299
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb0eb9a7f59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff42b6ec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 6d616e74726f6873 RCX: 00007fb0eb9a7f59
RDX: 00000000200005c0 RSI: 0000000020000580 RDI: 0000000020000540
RBP: 0031656c69662f2e R08: 0000000000000000 R09: 00005555899304c0
R10: 0000000000200000 R11: 0000000000000246 R12: 74616c785f696e75
R13: 746e6e69773d656d R14: 646578696d3d656d R15: 00007fb0eb9f103b
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90002d7f9f8 EFLAGS: 00010293
RAX: ffffffff81cb4ee0 RBX: 0000000000000000 RCX: ffff88801e428000
RDX: 0000000000000000 RSI: ffffea00004bfec0 RDI: 0000000000000000
RBP: ffffc90002d7fac0 R08: ffffea00004bfec7 R09: 1ffffd4000097fd8
R10: dffffc0000000000 R11: 0000000000000000 R12: ffffea00004bfec0
R13: 1ffffd4000097fd9 R14: 0000000000000000 R15: ffffea00004bfec8
FS:  000055558992f380(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000011be2000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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