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 5e5268807a1ceb521f673ca05ec3233389a97f61..301f10c9b563065907baef547929dca5d90b88ae 100644 (file)
--- 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 bbf1c8fb8511c70220c4a2b7c046f6007cf525b5..1f96efd30816d23227d0a703b16f3417c54098ab 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -802,8 +802,10 @@ 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/include/net/ping.h b/include/net/ping.h
index 5db0224b73ac47b1513ffb9361e48aa0167bb24d..2b496e9f9ebd74909d2056b97c4664653de84b86 100644 (file)
--- 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 d9c4f113d7093bba7eba2beefc31cd0af4b9bb95..23e6ab0a2dc0ea070b6a86548b7761f7dbda00d4 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 708c4a1be7a0651186958a9fe073b0fb8199760d..fc611e5fb04f16c3ddd3e73651f9e75603364747 100644 (file)
--- 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 ca4c3f1ad4dce745a88c36e87a2660599a0d980c..7d3db7838e6252cb0d246189f83a5c00281d3c37 100644 (file)
--- 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 a7003dea88f1488a76babeea4e6c316fc0dd6985..1ef87946714df873f5884ed679c58456a803d7e4 100644 (file)
--- 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 48b6bd2a9a1451b7adf9a678ccce859003d57a79..7a0fd804cbd7d2211327b53e78493e69d404ed0c 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/ping.c b/net/ipv6/ping.c
index 18f19df4189f19734564b5fcfbd46ec22b67a1e8..7856e962a3e6b60b9bfdefb531875138990da7fb 100644 (file)
--- 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 2f303bfd445f92f8570aac0f5283ce368810f1cd..430067cb9210d59b36899539436bc833034e98e9 100644 (file)
--- 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 a59beed5d04bbe2602d8c25bc6281033b6ff3799..3d2758d4494e3cb8eff9e958dcde49a9bd7bb7ec 100644 (file)
--- 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 b8a6039314e868781d3130f06fbb78ced6c4a678..e6e8408c9e3670b2303625e96a1154f34b07ef1b 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)