[PATCH v2] [RFC] can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

[PATCH v2] [RFC] can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

[Oliver Hartkopp]

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")
Link: https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t
Reported-by: Richard Weinberger <richard@nod.at>
Suggested-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---
 net/can/bcm.c   | 10 ++++++----
 net/can/isotp.c | 11 +++++++----
 net/can/raw.c   | 14 ++++++++------
 3 files changed, 21 insertions(+), 14 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
@@ -84,10 +84,12 @@
 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
 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
  * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
  */
@@ -1290,11 +1292,11 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 
 	if (!ifindex && msg->msg_name) {
 		/* 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)
 			return -EINVAL;
 
@@ -1532,11 +1534,11 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
 	struct sock *sk = sock->sk;
 	struct bcm_sock *bo = bcm_sk(sk);
 	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);
 
 	if (bo->bound) {
@@ -1614,12 +1616,12 @@ 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);
 	}
 
 	skb_free_datagram(sk, skb);
 
diff --git a/net/can/isotp.c b/net/can/isotp.c
index 3ef7f78e553b..86945dbb6c76 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -75,10 +75,12 @@
 MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
 MODULE_ALIAS("can-proto-6");
 
+#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
+
 #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
 			 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
 			 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
 
 /* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
@@ -987,11 +989,12 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	}
 
 	sock_recv_timestamp(msg, sk, skb);
 
 	if (msg->msg_name) {
-		msg->msg_namelen = sizeof(struct sockaddr_can);
+		__sockaddr_check_size(ISOTP_MIN_NAMELEN);
+		msg->msg_namelen = ISOTP_MIN_NAMELEN;
 		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 	}
 
 	skb_free_datagram(sk, skb);
 
@@ -1057,11 +1060,11 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 	struct net_device *dev;
 	int err = 0;
 	int notify_enetdown = 0;
 	int do_rx_reg = 1;
 
-	if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp))
+	if (len < ISOTP_MIN_NAMELEN)
 		return -EINVAL;
 
 	/* do not register frame reception for functional addressing */
 	if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
 		do_rx_reg = 0;
@@ -1153,17 +1156,17 @@ static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
 	struct isotp_sock *so = isotp_sk(sk);
 
 	if (peer)
 		return -EOPNOTSUPP;
 
-	memset(addr, 0, sizeof(*addr));
+	memset(addr, 0, ISOTP_MIN_NAMELEN);
 	addr->can_family = AF_CAN;
 	addr->can_ifindex = so->ifindex;
 	addr->can_addr.tp.rx_id = so->rxid;
 	addr->can_addr.tp.tx_id = so->txid;
 
-	return sizeof(*addr);
+	return ISOTP_MIN_NAMELEN;
 }
 
 static int isotp_setsockopt(struct socket *sock, int level, int optname,
 			    sockptr_t optval, unsigned int optlen)
 {
diff --git a/net/can/raw.c b/net/can/raw.c
index 37b47a39a3ed..139d9471ddcf 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -58,10 +58,12 @@
 MODULE_DESCRIPTION("PF_CAN raw protocol");
 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
  * the CAN frames matching that filter.  If the filter list is empty,
  * no CAN frames will be received by the socket.  The default after
@@ -392,11 +394,11 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 	struct raw_sock *ro = raw_sk(sk);
 	int ifindex;
 	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;
 
 	lock_sock(sk);
@@ -473,15 +475,15 @@ static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
 	struct raw_sock *ro = raw_sk(sk);
 
 	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,
 			  sockptr_t optval, unsigned int optlen)
 {
@@ -737,11 +739,11 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 	int err;
 
 	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)
 			return -EINVAL;
 
@@ -830,12 +832,12 @@ 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);
 	}
 
 	/* assign the flags that have been recorded in raw_rcv() */
 	msg->msg_flags |= *(raw_flags(skb));
-- 
2.30.2

Re: [PATCH v2] [RFC] can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

[Kurt Van Dijck]

Acked-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>

On Thu, 25 Mar 2021 09:13:26 +0100, Oliver Hartkopp wrote:
> 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")
> Link: https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t
> Reported-by: Richard Weinberger <richard@nod.at>
> Suggested-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
> ---
>  net/can/bcm.c   | 10 ++++++----
>  net/can/isotp.c | 11 +++++++----
>  net/can/raw.c   | 14 ++++++++------
>  3 files changed, 21 insertions(+), 14 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
> @@ -84,10 +84,12 @@
>  MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
>  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
>   * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
>   */
> @@ -1290,11 +1292,11 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
>  
>  	if (!ifindex && msg->msg_name) {
>  		/* 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)
>  			return -EINVAL;
>  
> @@ -1532,11 +1534,11 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
>  	struct sock *sk = sock->sk;
>  	struct bcm_sock *bo = bcm_sk(sk);
>  	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);
>  
>  	if (bo->bound) {
> @@ -1614,12 +1616,12 @@ 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);
>  	}
>  
>  	skb_free_datagram(sk, skb);
>  
> diff --git a/net/can/isotp.c b/net/can/isotp.c
> index 3ef7f78e553b..86945dbb6c76 100644
> --- a/net/can/isotp.c
> +++ b/net/can/isotp.c
> @@ -75,10 +75,12 @@
>  MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
>  MODULE_LICENSE("Dual BSD/GPL");
>  MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
>  MODULE_ALIAS("can-proto-6");
>  
> +#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
> +
>  #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
>  			 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
>  			 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
>  
>  /* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
> @@ -987,11 +989,12 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
>  	}
>  
>  	sock_recv_timestamp(msg, sk, skb);
>  
>  	if (msg->msg_name) {
> -		msg->msg_namelen = sizeof(struct sockaddr_can);
> +		__sockaddr_check_size(ISOTP_MIN_NAMELEN);
> +		msg->msg_namelen = ISOTP_MIN_NAMELEN;
>  		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
>  	}
>  
>  	skb_free_datagram(sk, skb);
>  
> @@ -1057,11 +1060,11 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
>  	struct net_device *dev;
>  	int err = 0;
>  	int notify_enetdown = 0;
>  	int do_rx_reg = 1;
>  
> -	if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp))
> +	if (len < ISOTP_MIN_NAMELEN)
>  		return -EINVAL;
>  
>  	/* do not register frame reception for functional addressing */
>  	if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
>  		do_rx_reg = 0;
> @@ -1153,17 +1156,17 @@ static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
>  	struct isotp_sock *so = isotp_sk(sk);
>  
>  	if (peer)
>  		return -EOPNOTSUPP;
>  
> -	memset(addr, 0, sizeof(*addr));
> +	memset(addr, 0, ISOTP_MIN_NAMELEN);
>  	addr->can_family = AF_CAN;
>  	addr->can_ifindex = so->ifindex;
>  	addr->can_addr.tp.rx_id = so->rxid;
>  	addr->can_addr.tp.tx_id = so->txid;
>  
> -	return sizeof(*addr);
> +	return ISOTP_MIN_NAMELEN;
>  }
>  
>  static int isotp_setsockopt(struct socket *sock, int level, int optname,
>  			    sockptr_t optval, unsigned int optlen)
>  {
> diff --git a/net/can/raw.c b/net/can/raw.c
> index 37b47a39a3ed..139d9471ddcf 100644
> --- a/net/can/raw.c
> +++ b/net/can/raw.c
> @@ -58,10 +58,12 @@
>  MODULE_DESCRIPTION("PF_CAN raw protocol");
>  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
>   * the CAN frames matching that filter.  If the filter list is empty,
>   * no CAN frames will be received by the socket.  The default after
> @@ -392,11 +394,11 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
>  	struct raw_sock *ro = raw_sk(sk);
>  	int ifindex;
>  	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;
>  
>  	lock_sock(sk);
> @@ -473,15 +475,15 @@ static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
>  	struct raw_sock *ro = raw_sk(sk);
>  
>  	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,
>  			  sockptr_t optval, unsigned int optlen)
>  {
> @@ -737,11 +739,11 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
>  	int err;
>  
>  	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)
>  			return -EINVAL;
>  
> @@ -830,12 +832,12 @@ 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);
>  	}
>  
>  	/* assign the flags that have been recorded in raw_rcv() */
>  	msg->msg_flags |= *(raw_flags(skb));
> -- 
> 2.30.2
> 

Re: [PATCH v2] [RFC] can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

[Oliver Hartkopp]

Thanks Kurt!

@Marc: Would you suggest to split this patch in two parts (raw, bcm) and 
(isotp) - as it would simplify the stable process?

isotp emerged in 5.10 while the j1939 (and the CAN_REQUIRED_SIZE macro) 
existed since 5.4

Regards,
Oliver

On 25.03.21 09:47, Kurt Van Dijck wrote:
> Acked-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
> 
> On Thu, 25 Mar 2021 09:13:26 +0100, Oliver Hartkopp wrote:
>> 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")
>> Link: https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t
>> Reported-by: Richard Weinberger <richard@nod.at>
>> Suggested-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
>> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
>> ---
>>   net/can/bcm.c   | 10 ++++++----
>>   net/can/isotp.c | 11 +++++++----
>>   net/can/raw.c   | 14 ++++++++------
>>   3 files changed, 21 insertions(+), 14 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
>> @@ -84,10 +84,12 @@
>>   MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
>>   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
>>    * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
>>    */
>> @@ -1290,11 +1292,11 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
>>   
>>   	if (!ifindex && msg->msg_name) {
>>   		/* 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)
>>   			return -EINVAL;
>>   
>> @@ -1532,11 +1534,11 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
>>   	struct sock *sk = sock->sk;
>>   	struct bcm_sock *bo = bcm_sk(sk);
>>   	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);
>>   
>>   	if (bo->bound) {
>> @@ -1614,12 +1616,12 @@ 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);
>>   	}
>>   
>>   	skb_free_datagram(sk, skb);
>>   
>> diff --git a/net/can/isotp.c b/net/can/isotp.c
>> index 3ef7f78e553b..86945dbb6c76 100644
>> --- a/net/can/isotp.c
>> +++ b/net/can/isotp.c
>> @@ -75,10 +75,12 @@
>>   MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
>>   MODULE_LICENSE("Dual BSD/GPL");
>>   MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
>>   MODULE_ALIAS("can-proto-6");
>>   
>> +#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
>> +
>>   #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
>>   			 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
>>   			 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
>>   
>>   /* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
>> @@ -987,11 +989,12 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
>>   	}
>>   
>>   	sock_recv_timestamp(msg, sk, skb);
>>   
>>   	if (msg->msg_name) {
>> -		msg->msg_namelen = sizeof(struct sockaddr_can);
>> +		__sockaddr_check_size(ISOTP_MIN_NAMELEN);
>> +		msg->msg_namelen = ISOTP_MIN_NAMELEN;
>>   		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
>>   	}
>>   
>>   	skb_free_datagram(sk, skb);
>>   
>> @@ -1057,11 +1060,11 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
>>   	struct net_device *dev;
>>   	int err = 0;
>>   	int notify_enetdown = 0;
>>   	int do_rx_reg = 1;
>>   
>> -	if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp))
>> +	if (len < ISOTP_MIN_NAMELEN)
>>   		return -EINVAL;
>>   
>>   	/* do not register frame reception for functional addressing */
>>   	if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
>>   		do_rx_reg = 0;
>> @@ -1153,17 +1156,17 @@ static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
>>   	struct isotp_sock *so = isotp_sk(sk);
>>   
>>   	if (peer)
>>   		return -EOPNOTSUPP;
>>   
>> -	memset(addr, 0, sizeof(*addr));
>> +	memset(addr, 0, ISOTP_MIN_NAMELEN);
>>   	addr->can_family = AF_CAN;
>>   	addr->can_ifindex = so->ifindex;
>>   	addr->can_addr.tp.rx_id = so->rxid;
>>   	addr->can_addr.tp.tx_id = so->txid;
>>   
>> -	return sizeof(*addr);
>> +	return ISOTP_MIN_NAMELEN;
>>   }
>>   
>>   static int isotp_setsockopt(struct socket *sock, int level, int optname,
>>   			    sockptr_t optval, unsigned int optlen)
>>   {
>> diff --git a/net/can/raw.c b/net/can/raw.c
>> index 37b47a39a3ed..139d9471ddcf 100644
>> --- a/net/can/raw.c
>> +++ b/net/can/raw.c
>> @@ -58,10 +58,12 @@
>>   MODULE_DESCRIPTION("PF_CAN raw protocol");
>>   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
>>    * the CAN frames matching that filter.  If the filter list is empty,
>>    * no CAN frames will be received by the socket.  The default after
>> @@ -392,11 +394,11 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
>>   	struct raw_sock *ro = raw_sk(sk);
>>   	int ifindex;
>>   	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;
>>   
>>   	lock_sock(sk);
>> @@ -473,15 +475,15 @@ static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
>>   	struct raw_sock *ro = raw_sk(sk);
>>   
>>   	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,
>>   			  sockptr_t optval, unsigned int optlen)
>>   {
>> @@ -737,11 +739,11 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
>>   	int err;
>>   
>>   	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)
>>   			return -EINVAL;
>>   
>> @@ -830,12 +832,12 @@ 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);
>>   	}
>>   
>>   	/* assign the flags that have been recorded in raw_rcv() */
>>   	msg->msg_flags |= *(raw_flags(skb));
>> -- 
>> 2.30.2
>>

Re: [PATCH v2] [RFC] can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

[Marc Kleine-Budde]

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On 25.03.2021 10:11:56, Oliver Hartkopp wrote:
> Thanks Kurt!
> 
> @Marc: Would you suggest to split this patch in two parts (raw, bcm) and
> (isotp) - as it would simplify the stable process?

Yes, make it so.

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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Re: [PATCH v2] [RFC] can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

[Richard Weinberger]

----- Ursprüngliche Mail -----
> Von: "Oliver Hartkopp" <socketcan@hartkopp.net>
> An: "linux-can" <linux-can@vger.kernel.org>
> CC: "Oliver Hartkopp" <socketcan@hartkopp.net>, "richard" <richard@nod.at>, "Kurt Van Dijck"
> <dev.kurt@vandijck-laurijssen.be>
> Gesendet: Donnerstag, 25. März 2021 09:13:26
> Betreff: [PATCH v2] [RFC] can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

> 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")
> Link:
> https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t
> Reported-by: Richard Weinberger <richard@nod.at>
> Suggested-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
> ---
> net/can/bcm.c   | 10 ++++++----
> net/can/isotp.c | 11 +++++++----
> net/can/raw.c   | 14 ++++++++------
> 3 files changed, 21 insertions(+), 14 deletions(-)

The patch unbreaks my application. :-)

Tested-by: Richard Weinberger <richard@nod.at>

Thanks,
//richard