Re: Taking strlen of buffers copied from userspace

[Robert Hancock]

Randy.Dunlap wrote:
> The latter one does (before the listed code):
>
>     memset(line, 0, LINE_SIZE);
>     if (len > LINE_SIZE)
>         len = LINE_SIZE;
>     if (copy_from_user(line, buf, len - 1))
>         return -EFAULT;
>
> so isn't line[LINE_SIZE - 1] always 0 ?

In that case, yes (I hadn't looked at the surrounding code). Rather an 
odd way of doing it, but shouldn't have that problem. Could still be 
subject to problems if buf contains a null at the first character, 
unless they're somehow preventing that too..

--
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@xxxxxxxxxxxxx
Home Page: http://www.roberthancock.com/

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/