[moderation] [ocfs2?] general protection fault in ocfs2_assure_trans_credits (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 192c0159402e Merge tag 'powerpc-7.0-1' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15eea15a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=306bfcc46aa00667
dashboard link: https://syzkaller.appspot.com/bug?extid=db62c97b96f1adb25d45
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
CC: [jl...@evilplan.org jose...@linux.alibaba.com linux-...@vger.kernel.org ma...@fasheh.com ocfs2...@lists.linux.dev]

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-192c0159.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/65d851846bea/vmlinux-192c0159.xz
kernel image: https://storage.googleapis.com/syzbot-assets/227621683c63/bzImage-192c0159.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+db62c9...@syzkaller.appspotmail.com

(syz.0.0,5319,0):ocfs2_extend_trans:460 ERROR: status = -30
(syz.0.0,5319,0):ocfs2_try_to_merge_extent:3817 ERROR: status = -30
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 5319 Comm: syz.0.0 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:jbd2_handle_buffer_credits include/linux/jbd2.h:-1 [inline]
RIP: 0010:ocfs2_assure_trans_credits+0x7d/0x350 fs/ocfs2/journal.c:479
Code: 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 97 a6 73 fe 4d 8b 3e eb 08 e8 8d ec 08 fe 4d 89 f7 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 74 a6 73 fe 4d 8b 3f 49 8d 7e 10
RSP: 0018:ffffc9000e7eeca8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000100000
RDX: ffffc90020031000 RSI: 0000000000049cb5 RDI: 0000000000049cb6
RBP: 0000000000000000 R08: ffff888035960000 R09: 0000000000000006
R10: 00000000fffffffc R11: 0000000000000002 R12: ffff88805700fbb0
R13: dffffc0000000000 R14: ffff88805700fbb0 R15: 0000000000000000
FS: 00007fb50247c6c0(0000) GS:ffff88808cabd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000ae000 CR3: 000000003815f000 CR4: 0000000000352ef0
Call Trace:
<TASK>
ocfs2_dio_end_io_write fs/ocfs2/aops.c:2345 [inline]
ocfs2_dio_end_io+0xbb5/0x1210 fs/ocfs2/aops.c:2404
dio_complete+0x25b/0x790 fs/direct-io.c:281
__blockdev_direct_IO+0x2cb0/0x32f0 fs/direct-io.c:1303
ocfs2_direct_IO+0x251/0x2c0 fs/ocfs2/aops.c:2441
generic_file_direct_write+0x1db/0x3e0 mm/filemap.c:4248
__generic_file_write_iter+0x11d/0x230 mm/filemap.c:4417
ocfs2_file_write_iter+0x1663/0x1e20 fs/ocfs2/file.c:2476
iter_file_splice_write+0x99b/0x1100 fs/splice.c:738
do_splice_from fs/splice.c:938 [inline]
direct_splice_actor+0x101/0x160 fs/splice.c:1161
splice_direct_to_actor+0x53a/0xc70 fs/splice.c:1105
do_splice_direct_actor fs/splice.c:1204 [inline]
do_splice_direct+0x195/0x290 fs/splice.c:1230
do_sendfile+0x535/0x7d0 fs/read_write.c:1372
__do_sys_sendfile64 fs/read_write.c:1433 [inline]
__se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb50159bf79
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:00007fb50247c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fb501816090 RCX: 00007fb50159bf79
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000006
RBP: 00007fb5016327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000080000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb501816128 R14: 00007fb501816090 R15: 00007ffc8d0afe38
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:jbd2_handle_buffer_credits include/linux/jbd2.h:-1 [inline]
RIP: 0010:ocfs2_assure_trans_credits+0x7d/0x350 fs/ocfs2/journal.c:479
Code: 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 97 a6 73 fe 4d 8b 3e eb 08 e8 8d ec 08 fe 4d 89 f7 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 74 a6 73 fe 4d 8b 3f 49 8d 7e 10
RSP: 0018:ffffc9000e7eeca8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000100000
RDX: ffffc90020031000 RSI: 0000000000049cb5 RDI: 0000000000049cb6
RBP: 0000000000000000 R08: ffff888035960000 R09: 0000000000000006
R10: 00000000fffffffc R11: 0000000000000002 R12: ffff88805700fbb0
R13: dffffc0000000000 R14: ffff88805700fbb0 R15: 0000000000000000
FS: 00007fb50247c6c0(0000) GS:ffff88808cabd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b7cfd3f168 CR3: 000000003815f000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 4c 89 f0 mov %r14,%rax
3: 48 c1 e8 03 shr $0x3,%rax
7: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
c: 74 08 je 0x16
e: 4c 89 f7 mov %r14,%rdi
11: e8 97 a6 73 fe call 0xfe73a6ad
16: 4d 8b 3e mov (%r14),%r15
19: eb 08 jmp 0x23
1b: e8 8d ec 08 fe call 0xfe08ecad
20: 4d 89 f7 mov %r14,%r15
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 ff mov %r15,%rdi
34: e8 74 a6 73 fe call 0xfe73a6ad
39: 4d 8b 3f mov (%r15),%r15
3c: 49 8d 7e 10 lea 0x10(%r14),%rdi


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