Re: [syzbot] [kernel?] UBSAN: shift-out-of-bounds in pcl726_attach

[Hillf Danton]

> Date: Sat, 05 Jul 2025 04:02:32 -0700
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    c435a4f487e8 Merge tag 'riscv-for-linus-6.16-rc5' of git:/..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=14ea4f70580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=5ba6cef8f153bfeb
> dashboard link: https://syzkaller.appspot.com/bug?extid=5cd373521edd68bebcb3
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1116c582580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12ea4f70580000

#syz test

--- x/drivers/comedi/drivers/pcl726.c
+++ y/drivers/comedi/drivers/pcl726.c
@@ -316,6 +316,8 @@ static int pcl726_attach(struct comedi_d
 	int ret;
 	int i;
 
+	if (it->options[1] < 0 || it->options[1] > 31)
+		return -EINVAL;
 	ret = comedi_request_region(dev, it->options[0], board->io_len);
 	if (ret)
 		return ret;
--