syzbot

divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 27 Comm: kworker/1:1 Not tainted 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_long flush_old_commits
RIP: 0010:do_journal_end+0x12b6/0x4890 fs/reiserfs/journal.c:4093
Code: 28 84 c0 0f 85 ab 2f 00 00 4a 8d 5c 32 01 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 b8 2f 00 00 41 8b 0f 48 89 d8 31 d2 <48> f7 f1 48 89 d3 48 03 5c 24 28 48 8b 84 24 e8 00 00 00 42 80 3c
RSP: 0018:ffffc90000a3f8e0 EFLAGS: 00010246
RAX: 0000000000000003 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802f9a6000
RBP: ffffc90000a3fb50 R08: dffffc0000000000 R09: ffff88802f9a6000
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880706e7017
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff8880706e7014
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc3e88be138 CR3: 000000002f4a3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 reiserfs_sync_fs fs/reiserfs/super.c:78 [inline]
 flush_old_commits+0x20d/0x2e0 fs/reiserfs/super.c:111
 process_one_work+0x917/0x1260 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:do_journal_end+0x12b6/0x4890 fs/reiserfs/journal.c:4093
Code: 28 84 c0 0f 85 ab 2f 00 00 4a 8d 5c 32 01 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 b8 2f 00 00 41 8b 0f 48 89 d8 31 d2 <48> f7 f1 48 89 d3 48 03 5c 24 28 48 8b 84 24 e8 00 00 00 42 80 3c
RSP: 0018:ffffc90000a3f8e0 EFLAGS: 00010246
RAX: 0000000000000003 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802f9a6000
RBP: ffffc90000a3fb50 R08: dffffc0000000000 R09: ffff88802f9a6000
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880706e7017
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff8880706e7014
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005563ac107098 CR3: 0000000030cee000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	28 84 c0 0f 85 ab 2f 	sub    %al,0x2fab850f(%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 b8 2f 00 00    	jne    0x2fda
  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 28       	add    0x28(%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