On Fri, Mar 07, 2014 at 12:42:12PM +0100, Vegard Nossum wrote: > On 03/07/2014 12:26 PM, Dan Carpenter wrote: > >On Fri, Mar 07, 2014 at 11:56:04AM +0100, Vegard Nossum wrote: > >>Both the in-kernel and BSD strlcpy() require that the source string is > >>NUL terminated. > > > >No. You're obviously wrong. What on earth? > > Well, from lib/string.c: > > size_t strlcpy(char *dest, const char *src, size_t size) > { > size_t ret = strlen(src); >
Ah... So you mean that we could read far beyond the end of the string and it would be a DoS because there would be 4 gigs of memory before we hit a NUL character. That won't happen in this case because the user only controls a small buffer. Normal memory is full of NUL chars. I don't know the speed impact of changing the strlen() there to strnlen(). > The BSD man page: > > "Also note that strlcpy() and strlcat() only operate on true ``C'' > strings. This means that for strlcpy() src must be NUL-terminated > and for strlcat() both src and dst must be NUL-terminated." It's talking about the kind of strings. If it's a string which includes NUL characters the strlcpy() won't work for that. Or if it is not *supposed* to end in a NUL character then it won't work for that. We are using C strings here. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/