[v5.15] divide error in drm_mode_debug_printmodeline

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 09996673e313 Linux 5.15.123
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1022d76ea80000
kernel config: https://syzkaller.appspot.com/x/.config?x=f9d4431ce682ac7e
dashboard link: https://syzkaller.appspot.com/bug?extid=0ce9593e9b1b1e16849e
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=11fc0c39a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1330a8b1a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e665cef1f596/disk-09996673.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c21eeab4b038/vmlinux-09996673.xz
kernel image: https://storage.googleapis.com/syzbot-assets/15e2b5a7aa32/bzImage-09996673.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0ce959...@syzkaller.appspotmail.com

divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 3500 Comm: syz-executor143 Not tainted 5.15.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
RIP: 0010:drm_mode_vrefresh drivers/gpu/drm/drm_modes.c:775 [inline]
RIP: 0010:drm_mode_debug_printmodeline+0x114/0x500 drivers/gpu/drm/drm_modes.c:56
Code: 00 41 0f b7 07 66 83 f8 02 b9 01 00 00 00 0f 43 c8 0f b7 c1 0f af e8 44 89 f0 48 69 c8 e8 03 00 00 89 e8 d1 e8 48 01 c8 31 d2 <48> f7 f5 49 89 c6 eb 0c e8 7f b9 ef fc eb 05 e8 78 b9 ef fc 48 89
RSP: 0018:ffffc90002d8f918 EFLAGS: 00010246
RAX: 000000000001f400 RBX: ffff888075827000 RCX: 000000000001f400
RDX: 0000000000000000 RSI: 0000000000008000 RDI: ffff888075827018
RBP: 0000000000000000 R08: ffffffff8490464b R09: ffffc90002d8f8e0
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000080 R14: 0000000000000080 R15: ffff888075827016
FS: 000055555610f380(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 0000000073262000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
drm_mode_setcrtc+0x825/0x1870 drivers/gpu/drm/drm_crtc.c:722
drm_ioctl_kernel+0x345/0x4f0 drivers/gpu/drm/drm_ioctl.c:801
drm_ioctl+0x60d/0x9d0 drivers/gpu/drm/drm_ioctl.c:904
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f0a4748b729
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffea74a36c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffea74a3898 RCX: 00007f0a4748b729
RDX: 0000000020000180 RSI: 00000000c06864a2 RDI: 0000000000000003
RBP: 00007f0a474fe610 R08: 00000000fffff4e6 R09: 00007ffea74a3898
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffea74a3888 R14: 0000000000000001 R15: 0000000000000001
</TASK>
Modules linked in:
---[ end trace 4074a93e295744a6 ]---
RIP: 0010:drm_mode_vrefresh drivers/gpu/drm/drm_modes.c:775 [inline]
RIP: 0010:drm_mode_debug_printmodeline+0x114/0x500 drivers/gpu/drm/drm_modes.c:56
Code: 00 41 0f b7 07 66 83 f8 02 b9 01 00 00 00 0f 43 c8 0f b7 c1 0f af e8 44 89 f0 48 69 c8 e8 03 00 00 89 e8 d1 e8 48 01 c8 31 d2 <48> f7 f5 49 89 c6 eb 0c e8 7f b9 ef fc eb 05 e8 78 b9 ef fc 48 89
RSP: 0018:ffffc90002d8f918 EFLAGS: 00010246
RAX: 000000000001f400 RBX: ffff888075827000 RCX: 000000000001f400
RDX: 0000000000000000 RSI: 0000000000008000 RDI: ffff888075827018
RBP: 0000000000000000 R08: ffffffff8490464b R09: ffffc90002d8f8e0
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000080 R14: 0000000000000080 R15: ffff888075827016
FS: 000055555610f380(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000560cdc784000 CR3: 0000000073262000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 41 0f add %al,0xf(%rcx)
3: b7 07 mov $0x7,%bh
5: 66 83 f8 02 cmp $0x2,%ax
9: b9 01 00 00 00 mov $0x1,%ecx
e: 0f 43 c8 cmovae %eax,%ecx
11: 0f b7 c1 movzwl %cx,%eax
14: 0f af e8 imul %eax,%ebp
17: 44 89 f0 mov %r14d,%eax
1a: 48 69 c8 e8 03 00 00 imul $0x3e8,%rax,%rcx
21: 89 e8 mov %ebp,%eax
23: d1 e8 shr %eax
25: 48 01 c8 add %rcx,%rax
28: 31 d2 xor %edx,%edx
* 2a: 48 f7 f5 div %rbp <-- trapping instruction
2d: 49 89 c6 mov %rax,%r14
30: eb 0c jmp 0x3e
32: e8 7f b9 ef fc call 0xfcefb9b6
37: eb 05 jmp 0x3e
39: e8 78 b9 ef fc call 0xfcefb9b6
3e: 48 rex.W
3f: 89 .byte 0x89


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