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: Ben Hutchings <ben@decadent.org.uk>

diff --git a/include/net/ip.h b/include/net/ip.h
index 06aed72023f7f1479dcbb0dbda4e9929b4ad75b2..b935e6ca5eb95e13a65e6567941cf348b2a5437c 100644 (file)
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -466,7 +466,7 @@ 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 4d549cfedf96d8cbc0e8259ffb95e6ccaba315a1..0580673d76ed6477da0dffb7273073da599f00d8 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -602,8 +602,10 @@ 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 3b360023a8219b872964defe5ee9e3401c27c64a..542a9c14cc342902e24765c8301c296d5524bb6f 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -374,7 +374,7 @@ 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;
@@ -411,6 +411,7 @@ 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 41fea2df2d046a34109d225a0b5061f974814737..a1f6b34a0e5c3be0a04446576b99a26f8d72083f 100644 (file)
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -632,7 +632,7 @@ 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 c676d07a8990ade8a423b4fff97441108cfe1fdc..cfded931accc3d3aeee545a724269ec6397c6130 100644 (file)
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -687,7 +687,7 @@ 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 239fb286570cf718ba8b11436b9c03358025b041..55098a635b1cdad09370f6813678c829121e9977 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1175,7 +1175,7 @@ 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 e2480691c220a16f93f602ce19266ffb2e7f017f..144c1053776bb43d33adcbc6ccc8d4fe5b563f83 100644 (file)
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -315,7 +315,7 @@ 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;
@@ -366,6 +366,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
                        ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
                                               &sin->sin6_addr);
                }
+               *addr_len = sizeof(*sin);
        }
 
        memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
@@ -418,7 +419,8 @@ out:
 /*
  *     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;
@@ -452,6 +454,7 @@ 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;
                ipv6_addr_copy(&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 3278f27f3dd168a8f64b8859a6eb38a09e99bbac..9ecbc846b31da7919f1319d904eecb8e07b30718 100644 (file)
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -457,10 +457,10 @@ 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 391329ebf03e2d54d33b85799d7a3517c3703201..f8bec1e5fd4a1c14d952977cc63216c3ab84d226 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -348,10 +348,10 @@ 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),