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can: bcm/raw: fix msg_namelen values depending on CAN_REQUIRED_SIZE
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[ Upstream commit 9e97147 ]

Since commit f5223e9 ("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: f5223e9 ("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>
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@hartkopp @gregkh
hartkopp authored and gregkh committed Apr 14, 2021
1 parent 58f8f10 commit 1d3837c
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Showing 2 changed files with 14 additions and 10 deletions.
10 changes: 6 additions & 4 deletions net/can/bcm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
}

Expand Down
14 changes: 8 additions & 6 deletions net/can/raw.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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);
}

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