[v6.1] divide error in do_journal_end

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4aa6747d9352 Linux 6.1.69
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15dc07cee80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1e9066810307299
dashboard link: https://syzkaller.appspot.com/bug?extid=9e58b6fea5933362e394
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=13841af9e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1505d291e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/209330361447/disk-4aa6747d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/48aa2c86988d/vmlinux-4aa6747d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/84320338eba6/bzImage-4aa6747d.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/27dcff150f6c/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e58b6...@syzkaller.appspotmail.com

REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 3546 Comm: syz-executor117 Not tainted 6.1.69-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:do_journal_end+0x1286/0x4870 fs/reiserfs/journal.c:4093
Code: 28 84 c0 0f 85 b8 2f 00 00 4a 8d 5c 32 01 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 c5 2f 00 00 41 8b 0f 48 89 d8 31 d2 <48> f7 f1 48 89 d3 48 03 5c 24 40 48 8b 84 24 e8 00 00 00 42 80 3c
RSP: 0018:ffffc90003a1f7e0 EFLAGS: 00010246
RAX: 0000000000000003 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807aac2000
RBP: ffffc90003a1fa50 R08: dffffc0000000000 R09: ffff88807aac2000
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807fd76017
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff88807fd76014
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020400000 CR3: 000000000ce8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
reiserfs_sync_fs+0xca/0x140 fs/reiserfs/super.c:78
sync_filesystem+0xe8/0x220 fs/sync.c:56
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7a/0xe0 fs/super.c:1459
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa73/0x26a0 kernel/exit.c:869
do_group_exit+0x202/0x2b0 kernel/exit.c:1019
__do_sys_exit_group kernel/exit.c:1030 [inline]
__se_sys_exit_group kernel/exit.c:1028 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ffb455a3809
Code: Unable to access opcode bytes at 0x7ffb455a37df.
RSP: 002b:00007ffc44ff7bc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007ffb455a3809
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007ffb456202d0 R08: ffffffffffffffb8 R09: 00007ffc44ff7ca0
R10: 00007ffc44ff7ca0 R11: 0000000000000246 R12: 00007ffb456202d0
R13: 0000000000000000 R14: 00007ffb45621040 R15: 00007ffb45571d60
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_journal_end+0x1286/0x4870 fs/reiserfs/journal.c:4093
Code: 28 84 c0 0f 85 b8 2f 00 00 4a 8d 5c 32 01 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 c5 2f 00 00 41 8b 0f 48 89 d8 31 d2 <48> f7 f1 48 89 d3 48 03 5c 24 40 48 8b 84 24 e8 00 00 00 42 80 3c
RSP: 0018:ffffc90003a1f7e0 EFLAGS: 00010246
RAX: 0000000000000003 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88807aac2000
RBP: ffffc90003a1fa50 R08: dffffc0000000000 R09: ffff88807aac2000
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807fd76017
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff88807fd76014
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff61f16cd0 CR3: 000000000ce8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 28 84 c0 0f 85 b8 2f sub %al,0x2fb8850f(%rax,%rax,8)
7: 00 00 add %al,(%rax)
9: 4a 8d 5c 32 01 lea 0x1(%rdx,%r14,1),%rbx
e: 4c 89 e0 mov %r12,%rax
11: 48 c1 e8 03 shr $0x3,%rax
15: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax
1a: 84 c0 test %al,%al
1c: 0f 85 c5 2f 00 00 jne 0x2fe7
22: 41 8b 0f mov (%r15),%ecx
25: 48 89 d8 mov %rbx,%rax
28: 31 d2 xor %edx,%edx
* 2a: 48 f7 f1 div %rcx <-- trapping instruction
2d: 48 89 d3 mov %rdx,%rbx
30: 48 03 5c 24 40 add 0x40(%rsp),%rbx
35: 48 8b 84 24 e8 00 00 mov 0xe8(%rsp),%rax
3c: 00
3d: 42 rex.X
3e: 80 .byte 0x80
3f: 3c .byte 0x3c


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