[syzbot] [jfs?] BUG: unable to handle kernel paging request in txAllocPMap

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a3d97d1d3fa6 Merge tag 'ovl-fixes-7.0-rc6' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=108101ca580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d46eab0cfd31c214
dashboard link: https://syzkaller.appspot.com/bug?extid=3179a62b064892f52d7e
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 (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-a3d97d1d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0f30a7749a53/vmlinux-a3d97d1d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7303c1241ecd/bzImage-a3d97d1d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3179a6...@syzkaller.appspotmail.com

blkno = 248b4d00, nblocks = 1b6685
ERROR: (device loop0): dbUpdatePMap: blocks are outside the map
ERROR: (device loop0): remounting filesystem as read-only
BUG: unable to handle page fault for address: ffff88800129f1d0
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD 1a806067 P4D 1a806067 PUD 1a807067 PMD 80000000012001a1
Oops: Oops: 0003 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 102 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:txAllocPMap+0x3d4/0x6b0 fs/jfs/jfs_txnmgr.c:2417
Code: 81 e5 ff ff ff 00 48 8b 7c 24 18 31 f6 48 89 ea 4c 89 e9 4c 8b 44 24 20 e8 b9 14 fb ff 42 0f b6 04 33 84 c0 0f 85 f7 00 00 00 <41> 80 24 24 fc 48 8b 44 24 28 42 0f b6 04 30 84 c0 0f 85 fb 00 00
RSP: 0018:ffffc90000e97bf8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff11000253e3a RCX: 4776158121b95000
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 00000000248b4d00 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1cbd630 R12: ffff88800129f1d0
R13: 00000000001b6685 R14: dffffc0000000000 R15: ffff88800129f1d0
FS: 0000000000000000(0000) GS:ffff88808ca4c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88800129f1d0 CR3: 000000000e54c000 CR4: 0000000000352ef0
Call Trace:
<TASK>
txUpdateMap+0x2a2/0x9c0 fs/jfs/jfs_txnmgr.c:2309
txLazyCommit fs/jfs/jfs_txnmgr.c:2665 [inline]
jfs_lazycommit+0x43d/0xaa0 fs/jfs/jfs_txnmgr.c:2734
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
CR2: ffff88800129f1d0
---[ end trace 0000000000000000 ]---
RIP: 0010:txAllocPMap+0x3d4/0x6b0 fs/jfs/jfs_txnmgr.c:2417
Code: 81 e5 ff ff ff 00 48 8b 7c 24 18 31 f6 48 89 ea 4c 89 e9 4c 8b 44 24 20 e8 b9 14 fb ff 42 0f b6 04 33 84 c0 0f 85 f7 00 00 00 <41> 80 24 24 fc 48 8b 44 24 28 42 0f b6 04 30 84 c0 0f 85 fb 00 00
RSP: 0018:ffffc90000e97bf8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff11000253e3a RCX: 4776158121b95000
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 00000000248b4d00 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1cbd630 R12: ffff88800129f1d0
R13: 00000000001b6685 R14: dffffc0000000000 R15: ffff88800129f1d0
FS: 0000000000000000(0000) GS:ffff88808ca4c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88800129f1d0 CR3: 000000000e54c000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 81 e5 ff ff ff 00 and $0xffffff,%ebp
6: 48 8b 7c 24 18 mov 0x18(%rsp),%rdi
b: 31 f6 xor %esi,%esi
d: 48 89 ea mov %rbp,%rdx
10: 4c 89 e9 mov %r13,%rcx
13: 4c 8b 44 24 20 mov 0x20(%rsp),%r8
18: e8 b9 14 fb ff call 0xfffb14d6
1d: 42 0f b6 04 33 movzbl (%rbx,%r14,1),%eax
22: 84 c0 test %al,%al
24: 0f 85 f7 00 00 00 jne 0x121
* 2a: 41 80 24 24 fc andb $0xfc,(%r12) <-- trapping instruction
2f: 48 8b 44 24 28 mov 0x28(%rsp),%rax
34: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax
39: 84 c0 test %al,%al
3b: 0f .byte 0xf
3c: 85 fb test %edi,%ebx


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