From: Eugene Syromiatnikov <esyr@redhat.com>
To: Jeremy Kerr <jk@codeconstruct.com.au>,
Matt Johnston <matt@codeconstruct.com.au>
Cc: "David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net-next 1/2] mctp: handle the struct sockaddr_mctp padding fields
Date: Mon, 1 Nov 2021 18:54:49 +0100 [thread overview]
Message-ID: <28f36bbcecc5b28e56cb33ff449c3ae92adebb8c.1635788968.git.esyr@redhat.com> (raw)
In-Reply-To: <cover.1635788968.git.esyr@redhat.com>
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(+)
diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
index d344b02..bc88159 100644
--- a/net/mctp/af_mctp.c
+++ b/net/mctp/af_mctp.c
@@ -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) {
--
2.1.4
next prev parent reply other threads:[~2021-11-01 17:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-01 17:54 [PATCH net-next 0/2] MCTP sockaddr padding check/initialisation fixup Eugene Syromiatnikov
2021-11-01 17:54 ` Eugene Syromiatnikov [this message]
2021-11-01 17:54 ` [PATCH net-next 2/2] mctp: handle the struct sockaddr_mctp_ext padding field Eugene Syromiatnikov
2021-11-03 0:55 ` Jakub Kicinski
2021-11-02 1:57 ` [PATCH net-next 0/2] MCTP sockaddr padding check/initialisation fixup Jeremy Kerr
2021-11-02 8:50 ` Eugene Syromiatnikov
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