Messages in this thread | | | Date | Mon, 5 Oct 2015 18:22:26 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] string: Improve the generic strlcpy() implementation |
| |
* Linus Torvalds <torvalds@linux-foundation.org> wrote:
> > 2) strscpy() will copy garbage past NUL from source into destination. It won't > > fault but still, who knows what lies after string. > > Yes, that's probably worth fixing before we get actual users..
Hm, this is the spot:
c = *(unsigned long *)(src+res); *(unsigned long *)(dest+res) = c;
if (has_zero(c, &data, &constants)) { data = prep_zero_mask(c, data, &constants); data = create_zero_mask(data); return res + find_zero(data); }
We could do something like:
c = *(unsigned long *)(src+res); *(unsigned long *)(dest+res) = c;
if (has_zero(c, &data, &constants)) { unsigned int zero_pos;
data = prep_zero_mask(c, data, &constants); data = create_zero_mask(data);
zero_pos = find_zero(data); res += zero_pos;
memset(dest+res, 0, sizeof(long)-zero_pos);
return res; }
I.e. the extra memset() clears out the partial word (if any) after the NUL.
Completely untested.
Thanks,
Ingo
| |