Bugzilla: 1035887

Upstream-status: 3.13

From 4be402ba6158068d53ab0268f1affa9d82dae2ec Mon Sep 17 00:00:00 2001

From: Hannes Frederic Sowa <hannes@stressinduktion.org>

Date: Fri, 22 Nov 2013 23:46:12 +0000

Subject: [PATCH] inet: fix addr_len/msg->msg_namelen assignment in recv_error

 and rxpmtu functions

Commit bceaa90240b6019ed73b49965eac7d167610be69 ("inet: prevent leakage

of uninitialized memory to user in recv syscalls") conditionally updated

addr_len if the msg_name is written to. The recv_error and rxpmtu

functions relied on the recvmsg functions to set up addr_len before.

As this does not happen any more we have to pass addr_len to those

functions as well and set it to the size of the corresponding sockaddr

length.

This broke traceroute and such.

Fixes: bceaa90240b6 ("inet: prevent leakage of uninitialized memory to user in recv syscalls")

Reported-by: Brad Spengler <spender@grsecurity.net>

Reported-by: Tom Labanowski

Cc: mpb <mpb.mail@gmail.com>

Cc: David S. Miller <davem@davemloft.net>

Cc: Eric Dumazet <eric.dumazet@gmail.com>

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Signed-off-by: David S. Miller <davem@davemloft.net>

---

 include/net/ip.h       | 2 +-

 include/net/ipv6.h     | 4 ++--

 include/net/ping.h     | 3 ++-

 net/ipv4/ip_sockglue.c | 3 ++-

 net/ipv4/ping.c        | 5 +++--

 net/ipv4/raw.c         | 2 +-

 net/ipv4/udp.c         | 2 +-

 net/ipv6/datagram.c    | 7 +++++--

 net/ipv6/ping.c        | 3 ++-

 net/ipv6/raw.c         | 4 ++--

 net/ipv6/udp.c         | 4 ++--

 net/l2tp/l2tp_ip6.c    | 2 +-

 12 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h

index 5e52688..301f10c 100644

--- a/include/net/ip.h

+++ b/include/net/ip.h

@@ -464,7 +464,7 @@ extern int	compat_ip_getsockopt(struct sock *sk, int level,

 			int optname, char __user *optval, int __user *optlen);

 extern int	ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));

-extern int 	ip_recv_error(struct sock *sk, struct msghdr *msg, int len);

+extern int 	ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);

 extern void	ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 

 			      __be16 port, u32 info, u8 *payload);

 extern void	ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,

diff --git a/include/net/ipv6.h b/include/net/ipv6.h

index bbf1c8f..5529d79 100644

--- a/include/net/ipv6.h

+++ b/include/net/ipv6.h

@@ -802,8 +802,8 @@ extern int			compat_ipv6_getsockopt(struct sock *sk,

 extern int			ip6_datagram_connect(struct sock *sk, 

 						     struct sockaddr *addr, int addr_len);

-extern int 			ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len);

-extern int 			ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len);

+extern int 			ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);

+extern int 			ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len, int *addr_len);

 extern void			ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,

 						u32 info, u8 *payload);

 extern void			ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);

diff --git a/include/net/ping.h b/include/net/ping.h

index 5db0224..2b496e9 100644

--- a/include/net/ping.h

+++ b/include/net/ping.h

@@ -31,7 +31,8 @@

 /* Compatibility glue so we can support IPv6 when it's compiled as a module */

 struct pingv6_ops {

-	int (*ipv6_recv_error)(struct sock *sk, struct msghdr *msg, int len);

+	int (*ipv6_recv_error)(struct sock *sk, struct msghdr *msg, int len,

+			       int *addr_len);

 	int (*ip6_datagram_recv_ctl)(struct sock *sk, struct msghdr *msg,

 				     struct sk_buff *skb);

 	int (*icmpv6_err_convert)(u8 type, u8 code, int *err);

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c

index d9c4f11..23e6ab0 100644

--- a/net/ipv4/ip_sockglue.c

+++ b/net/ipv4/ip_sockglue.c

@@ -368,7 +368,7 @@ void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 inf

 /*

  *	Handle MSG_ERRQUEUE

  */

-int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)

+int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)

 {

 	struct sock_exterr_skb *serr;

 	struct sk_buff *skb, *skb2;

@@ -405,6 +405,7 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)

 						   serr->addr_offset);

 		sin->sin_port = serr->port;

 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));

+		*addr_len = sizeof(*sin);

 	}

 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c

index 92fb6ff..ac31877 100644

--- a/net/ipv4/ping.c

+++ b/net/ipv4/ping.c

@@ -838,10 +838,11 @@ int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,

 	if (flags & MSG_ERRQUEUE) {

 		if (family == AF_INET) {

-			return ip_recv_error(sk, msg, len);

+			return ip_recv_error(sk, msg, len, addr_len);

 #if IS_ENABLED(CONFIG_IPV6)

 		} else if (family == AF_INET6) {

-			return pingv6_ops.ipv6_recv_error(sk, msg, len);

+			return pingv6_ops.ipv6_recv_error(sk, msg, len,

+							  addr_len);

 #endif

 		}

 	}

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c

index ca4c3f1..7d3db78 100644

--- a/net/ipv4/raw.c

+++ b/net/ipv4/raw.c

@@ -695,7 +695,7 @@ static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,

 		goto out;

 	if (flags & MSG_ERRQUEUE) {

-		err = ip_recv_error(sk, msg, len);

+		err = ip_recv_error(sk, msg, len, addr_len);

 		goto out;

 	}

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c

index a7003de..1ef8794 100644

--- a/net/ipv4/udp.c

+++ b/net/ipv4/udp.c

@@ -1210,7 +1210,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,

 	bool slow;

 	if (flags & MSG_ERRQUEUE)

-		return ip_recv_error(sk, msg, len);

+		return ip_recv_error(sk, msg, len, addr_len);

 try_again:

 	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c

index 48b6bd2..7a0fd80 100644

--- a/net/ipv6/datagram.c

+++ b/net/ipv6/datagram.c

@@ -318,7 +318,7 @@ void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)

 /*

  *	Handle MSG_ERRQUEUE

  */

-int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)

+int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)

 {

 	struct ipv6_pinfo *np = inet6_sk(sk);

 	struct sock_exterr_skb *serr;

@@ -369,6 +369,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)

 					       &sin->sin6_addr);

 			sin->sin6_scope_id = 0;

 		}

+		*addr_len = sizeof(*sin);

 	}

 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));

@@ -423,7 +424,8 @@ EXPORT_SYMBOL_GPL(ipv6_recv_error);

 /*

  *	Handle IPV6_RECVPATHMTU

  */

-int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len)

+int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,

+		     int *addr_len)

 {

 	struct ipv6_pinfo *np = inet6_sk(sk);

 	struct sk_buff *skb;

@@ -457,6 +459,7 @@ int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len)

 		sin->sin6_port = 0;

 		sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;

 		sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;

+		*addr_len = sizeof(*sin);

 	}

 	put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);

diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c

index 18f19df..7856e96 100644

--- a/net/ipv6/ping.c

+++ b/net/ipv6/ping.c

@@ -57,7 +57,8 @@ static struct inet_protosw pingv6_protosw = {

 /* Compatibility glue so we can support IPv6 when it's compiled as a module */

-static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)

+static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,

+				 int *addr_len)

 {

 	return -EAFNOSUPPORT;

 }

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c

index 2f303bf..430067c 100644

--- a/net/ipv6/raw.c

+++ b/net/ipv6/raw.c

@@ -467,10 +467,10 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,

 		return -EOPNOTSUPP;

 	if (flags & MSG_ERRQUEUE)

-		return ipv6_recv_error(sk, msg, len);

+		return ipv6_recv_error(sk, msg, len, addr_len);

 	if (np->rxpmtu && np->rxopt.bits.rxpmtu)

-		return ipv6_recv_rxpmtu(sk, msg, len);

+		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);

 	skb = skb_recv_datagram(sk, flags, noblock, &err;;

 	if (!skb)

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c

index a59beed..3d2758d 100644

--- a/net/ipv6/udp.c

+++ b/net/ipv6/udp.c

@@ -375,10 +375,10 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,

 	bool slow;

 	if (flags & MSG_ERRQUEUE)

-		return ipv6_recv_error(sk, msg, len);

+		return ipv6_recv_error(sk, msg, len, addr_len);

 	if (np->rxpmtu && np->rxopt.bits.rxpmtu)

-		return ipv6_recv_rxpmtu(sk, msg, len);

+		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);

 try_again:

 	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),

diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c

index b8a6039..e6e8408 100644

--- a/net/l2tp/l2tp_ip6.c

+++ b/net/l2tp/l2tp_ip6.c

@@ -665,7 +665,7 @@ static int l2tp_ip6_recvmsg(struct kiocb *iocb, struct sock *sk,

 		*addr_len = sizeof(*lsa);

 	if (flags & MSG_ERRQUEUE)

-		return ipv6_recv_error(sk, msg, len);

+		return ipv6_recv_error(sk, msg, len, addr_len);

 	skb = skb_recv_datagram(sk, flags, noblock, &err;;

 	if (!skb)

-- 

1.8.3.1