@@ -33,6 +33,12 @@ static int mctp_release(struct socket *sock)
return 0;
}
+/* Generic sockaddr checks, padding checks only so far */
+static bool mctp_sockaddr_is_ok(const struct sockaddr_mctp *addr)
+{
+ return !addr->__smctp_pad0 && !addr->__smctp_pad1;
+}
+
static int mctp_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
{
struct sock *sk = sock->sk;
@@ -52,6 +58,9 @@ static int mctp_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
/* it's a valid sockaddr for MCTP, cast and do protocol checks */
smctp = (struct sockaddr_mctp *)addr;
+ if (!mctp_sockaddr_is_ok(smctp))
+ return -EINVAL;
+
lock_sock(sk);
/* TODO: allow rebind */
@@ -87,6 +96,8 @@ static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
return -EINVAL;
if (addr->smctp_family != AF_MCTP)
return -EINVAL;
+ if (!mctp_sockaddr_is_ok(addr))
+ return -EINVAL;
if (addr->smctp_tag & ~(MCTP_TAG_MASK | MCTP_TAG_OWNER))
return -EINVAL;
@@ -198,11 +209,13 @@ static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
addr = msg->msg_name;
addr->smctp_family = AF_MCTP;
+ addr->__smctp_pad0 = 0;
addr->smctp_network = cb->net;
addr->smctp_addr.s_addr = hdr->src;
addr->smctp_type = type;
addr->smctp_tag = hdr->flags_seq_tag &
(MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
+ addr->__smctp_pad1 = 0;
msg->msg_namelen = sizeof(*addr);
if (msk->addr_ext) {
In order to have the padding fields actually usable in the future, there have to be checks that user space doesn't supply non-zero garbage there. It is also worth setting these padding fields to zero, unless it is known that they have been already zeroed. Cc: stable@vger.kernel.org # v5.15 Complements: 5a20dd46b8b84593 ("mctp: Be explicit about struct sockaddr_mctp padding") Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com> --- net/mctp/af_mctp.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)