From 4d8fe7376a12bf4524783dd95cbc00f1fece6232 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Mon, 30 Sep 2013 22:04:25 +0200 Subject: [PATCH] audit: use nlmsg_len() to get message payload length Using the nlmsg_len member of the netlink header to test if the message is valid is wrong as it includes the size of the netlink header itself. Thereby allowing to send short netlink messages that pass those checks. Use nlmsg_len() instead to test for the right message length. The result of nlmsg_len() is guaranteed to be non-negative as the netlink message already passed the checks of nlmsg_ok(). Also switch to min_t() to please checkpatch.pl. Cc: Al Viro Cc: Eric Paris Cc: stable@vger.kernel.org # v2.6.6+ for the 1st hunk, v2.6.23+ for the 2nd Signed-off-by: Mathias Krause Signed-off-by: Richard Guy Briggs Signed-off-by: Eric Paris --- kernel/audit.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index 3ce60e063aae..3ad14e6e00bd 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -771,7 +771,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) &status_set, sizeof(status_set)); break; case AUDIT_SET: - if (nlh->nlmsg_len < sizeof(struct audit_status)) + if (nlmsg_len(nlh) < sizeof(struct audit_status)) return -EINVAL; status_get = (struct audit_status *)data; if (status_get->mask & AUDIT_STATUS_ENABLED) { @@ -944,7 +944,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) memset(&s, 0, sizeof(s)); /* guard against past and future API changes */ - memcpy(&s, data, min(sizeof(s), (size_t)nlh->nlmsg_len)); + memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); if ((s.enabled != 0 && s.enabled != 1) || (s.log_passwd != 0 && s.log_passwd != 1)) return -EINVAL; -- 2.20.1