inet: fix addr_len/msg->msg_namelen assignment in recv_error and rxpmtu functions

[ Upstream commit 85fbaa75037d0b6b786ff18658ddf0b4014ce2a4 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/net/ip.h b/include/net/ip.h
index edfa591..788f1d8 100644 (file)
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -454,7 +454,7 @@ 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 0810aa5..9e093fc 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -793,8 +793,10 @@ 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/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index d9c4f11..23e6ab0 100644 (file)
--- 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 be01d5b..a475b30 100644 (file)
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -636,7 +636,7 @@ static int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                goto out;
 
        if (flags & MSG_ERRQUEUE)
-               return ip_recv_error(sk, msg, len);
+               return ip_recv_error(sk, msg, len, addr_len);
 
        skb = skb_recv_datagram(sk, flags, noblock, &err);
        if (!skb)

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 448e5a7..402870f 100644 (file)
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -693,7 +693,7 @@ 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 eeb3474..2e65ac8 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1208,7 +1208,7 @@ 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 4b56cbb..e0a30a7 100644 (file)
--- 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/raw.c b/net/ipv6/raw.c
index d3c01a6..464b1c9 100644 (file)
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -460,10 +460,10 @@ 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 f10f118..6b298dc 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -374,10 +374,10 @@ 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 (file)
--- 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)