3.11.10.8 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Pablo Neira <[email protected]> commit 8b7b932434f5eee495b91a2804f5b64ebb2bc835 upstream. nla_strcmp compares the string length plus one, so it's implicitly including the nul-termination in the comparison. int nla_strcmp(const struct nlattr *nla, const char *str) { int len = strlen(str) + 1; ... d = memcmp(nla_data(nla), str, len); However, if NLA_STRING is used, userspace can send us a string without the nul-termination. This is a problem since the string comparison will not match as the last byte may be not the nul-termination. Fix this by skipping the comparison of the nul-termination if the attribute data is nul-terminated. Suggested by Thomas Graf. Cc: Florian Westphal <[email protected]> Cc: Thomas Graf <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- lib/nlattr.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/lib/nlattr.c b/lib/nlattr.c index 18eca78..fc67547 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -303,9 +303,15 @@ int nla_memcmp(const struct nlattr *nla, const void *data, */ int nla_strcmp(const struct nlattr *nla, const char *str) { - int len = strlen(str) + 1; - int d = nla_len(nla) - len; + int len = strlen(str); + char *buf = nla_data(nla); + int attrlen = nla_len(nla); + int d; + if (attrlen > 0 && buf[attrlen - 1] == '\0') + attrlen--; + + d = attrlen - len; if (d == 0) d = memcmp(nla_data(nla), str, len); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
