[PATCH 5.11 126/210] can: bcm/raw: fix msg_namelen values depending on CAN_REQUIRED_SIZE

Greg Kroah-Hartman
2021-04-12T09:37:44Z

From: Oliver Hartkopp <socketcan@hartkopp.net>

[ Upstream commit 9e9714742fb70467464359693a73b911a630226f ]

Since commit f5223e9eee65 ("can: extend sockaddr_can to include j1939
members") the sockaddr_can has been extended in size and a new
CAN_REQUIRED_SIZE macro has been introduced to calculate the protocol
specific needed size.

The ABI for the msg_name and msg_namelen has not been adapted to the
new CAN_REQUIRED_SIZE macro for the other CAN protocols which leads to
a problem when an existing binary reads the (increased) struct
sockaddr_can in msg_name.

Fixes: f5223e9eee65 ("can: extend sockaddr_can to include j1939 members")
Reported-by: Richard Weinberger <richard@nod.at>
Tested-by: Richard Weinberger <richard@nod.at>
Acked-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Link: https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t
Link: https://lore.kernel.org/r/20210325125850.1620-1-socketcan@hartkopp.net
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/can/bcm.c | 10 ++++++----
net/can/raw.c | 14 ++++++++------
2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 0e5c37be4a2b..909b9e684e04 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -86,6 +86,8 @@ MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
MODULE_ALIAS("can-proto-2");

+#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
+
/*
* easy access to the first 64 bit of can(fd)_frame payload. cp->data is
* 64 bit aligned so the offset has to be multiples of 8 which is ensured
@@ -1292,7 +1294,7 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
/* no bound device as default => check msg_name */
DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);

- if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex))
+ if (msg->msg_namelen < BCM_MIN_NAMELEN)
return -EINVAL;

if (addr->can_family != AF_CAN)
@@ -1534,7 +1536,7 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
struct net *net = sock_net(sk);
int ret = 0;

- if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex))
+ if (len < BCM_MIN_NAMELEN)
return -EINVAL;

lock_sock(sk);
@@ -1616,8 +1618,8 @@ static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
sock_recv_ts_and_drops(msg, sk, skb);

if (msg->msg_name) {
- __sockaddr_check_size(sizeof(struct sockaddr_can));
- msg->msg_namelen = sizeof(struct sockaddr_can);
+ __sockaddr_check_size(BCM_MIN_NAMELEN);
+ msg->msg_namelen = BCM_MIN_NAMELEN;
memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
}

diff --git a/net/can/raw.c b/net/can/raw.c
index 6ec8aa1d0da4..95113b0898b2 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -60,6 +60,8 @@ MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
MODULE_ALIAS("can-proto-1");

+#define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
+
#define MASK_ALL 0

/* A raw socket has a list of can_filters attached to it, each receiving
@@ -394,7 +396,7 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
int err = 0;
int notify_enetdown = 0;

- if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex))
+ if (len < RAW_MIN_NAMELEN)
return -EINVAL;
if (addr->can_family != AF_CAN)
return -EINVAL;
@@ -475,11 +477,11 @@ static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
if (peer)
return -EOPNOTSUPP;

- memset(addr, 0, sizeof(*addr));
+ memset(addr, 0, RAW_MIN_NAMELEN);
addr->can_family = AF_CAN;
addr->can_ifindex = ro->ifindex;

- return sizeof(*addr);
+ return RAW_MIN_NAMELEN;
}

static int raw_setsockopt(struct socket *sock, int level, int optname,
@@ -731,7 +733,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);

- if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex))
+ if (msg->msg_namelen < RAW_MIN_NAMELEN)
return -EINVAL;

if (addr->can_family != AF_CAN)
@@ -824,8 +826,8 @@ static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
sock_recv_ts_and_drops(msg, sk, skb);

if (msg->msg_name) {
- __sockaddr_check_size(sizeof(struct sockaddr_can));
- msg->msg_namelen = sizeof(struct sockaddr_can);
+ __sockaddr_check_size(RAW_MIN_NAMELEN);
+ msg->msg_namelen = RAW_MIN_NAMELEN;
memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
}

--
2.30.2