[syzbot] [reiserfs?] divide error in flush_journal_list

From: syzbot
Date: Wed Mar 08 2023 - 13:05:46 EST


Hello,

syzbot found the following issue on:

HEAD commit: 0988a0ea7919 Merge tag 'for-v6.3-part2' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10a0bee4c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=f763d89e26d3d4c4
dashboard link: https://syzkaller.appspot.com/bug?extid=c559e4d7d61c16608cb1
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e0aa29e9ae74/disk-0988a0ea.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6f64db0b58ef/vmlinux-0988a0ea.xz
kernel image: https://storage.googleapis.com/syzbot-assets/db391408e15d/bzImage-0988a0ea.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c559e4d7d61c16608cb1@xxxxxxxxxxxxxxxxxxxxxxxxx

divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9856 Comm: syz-executor.3 Not tainted 6.2.0-syzkaller-13467-g0988a0ea7919 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
RIP: 0010:flush_journal_list+0x1045/0x1c70 fs/reiserfs/journal.c:1592
Code: c0 0f 85 eb 0a 00 00 4f 8d 7c 3e 02 48 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 4d 89 e6 0f 85 ee 0a 00 00 8b 0b 4c 89 f8 31 d2 <48> f7 f1 48 89 d3 43 0f b6 44 35 00 84 c0 0f 85 f2 0a 00 00 48 8b
RSP: 0018:ffffc900167a7558 EFLAGS: 00010246
RAX: 00000000000001a4 RBX: ffff88802eb1c014 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88802eb1c017 R08: ffffffff8232797b R09: ffffed100f275e0d
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff110045e5117 R14: dffffc0000000000 R15: 00000000000001a4
FS: 00007f3a7e67f700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4ac8868000 CR3: 0000000029317000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
flush_used_journal_lists+0x1256/0x15d0 fs/reiserfs/journal.c:1829
do_journal_end+0x39f7/0x4770
do_journal_begin_r+0x970/0x1020
journal_begin+0x14c/0x360 fs/reiserfs/journal.c:3255
__commit_trans_jl fs/reiserfs/journal.c:3866 [inline]
reiserfs_commit_for_inode+0x736/0xbe0 fs/reiserfs/journal.c:3922
reiserfs_dir_fsync+0xcb/0x100 fs/reiserfs/dir.c:43
vfs_fsync_range fs/sync.c:188 [inline]
vfs_fsync fs/sync.c:202 [inline]
do_fsync fs/sync.c:212 [inline]
__do_sys_fdatasync fs/sync.c:225 [inline]
__se_sys_fdatasync fs/sync.c:223 [inline]
__x64_sys_fdatasync+0xb5/0x110 fs/sync.c:223
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f3a7d88c0f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007f3a7e67f168 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: ffffffffffffffda RBX: 00007f3a7d9abf80 RCX: 00007f3a7d88c0f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f3a7d8e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffec0b306af R14: 00007f3a7e67f300 R15: 0000000000022000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:flush_journal_list+0x1045/0x1c70 fs/reiserfs/journal.c:1592
Code: c0 0f 85 eb 0a 00 00 4f 8d 7c 3e 02 48 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 4d 89 e6 0f 85 ee 0a 00 00 8b 0b 4c 89 f8 31 d2 <48> f7 f1 48 89 d3 43 0f b6 44 35 00 84 c0 0f 85 f2 0a 00 00 48 8b
RSP: 0018:ffffc900167a7558 EFLAGS: 00010246
RAX: 00000000000001a4 RBX: ffff88802eb1c014 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88802eb1c017 R08: ffffffff8232797b R09: ffffed100f275e0d
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff110045e5117 R14: dffffc0000000000 R15: 00000000000001a4
FS: 00007f3a7e67f700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f82a9f80000 CR3: 0000000029317000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: c0 0f 85 rorb $0x85,(%rdi)
3: eb 0a jmp 0xf
5: 00 00 add %al,(%rax)
7: 4f 8d 7c 3e 02 lea 0x2(%r14,%r15,1),%r15
c: 48 89 e8 mov %rbp,%rax
f: 48 c1 e8 03 shr $0x3,%rax
13: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax
18: 84 c0 test %al,%al
1a: 4d 89 e6 mov %r12,%r14
1d: 0f 85 ee 0a 00 00 jne 0xb11
23: 8b 0b mov (%rbx),%ecx
25: 4c 89 f8 mov %r15,%rax
28: 31 d2 xor %edx,%edx
* 2a: 48 f7 f1 div %rcx <-- trapping instruction
2d: 48 89 d3 mov %rdx,%rbx
30: 43 0f b6 44 35 00 movzbl 0x0(%r13,%r14,1),%eax
36: 84 c0 test %al,%al
38: 0f 85 f2 0a 00 00 jne 0xb30
3e: 48 rex.W
3f: 8b .byte 0x8b


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.