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>

diff --git a/include/net/ip.h b/include/net/ip.h
index 217bc5bfc6c6e99cf52117312ceda95c98f005a6..5a25f36fe3a7cb50a388e309df9b5905f013b6b4 100644 (file)
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -473,7 +473,7 @@ int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 int ip_ra_control(struct sock *sk, unsigned char on,
                  void (*destructor)(struct sock *));
 
-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);
 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
                   u32 info, u8 *payload);
 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 2a5f668cd6836fae6ff45e551f8dacfd93dacd8e..eb198acaac1d5f42b53ac97838511563fe7e874b 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -776,8 +776,10 @@ int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
 
 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
 
-int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len);
-int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len);
+int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
+                   int *addr_len);
+int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
+                    int *addr_len);
 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
                     u32 info, u8 *payload);
 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 3f67704f3747281b3ad0852fd5d69dcd49c9b01c..90f48417b03dac91259aefe18d79c63145a23849 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 3f858266fa7e33a0941a135ec8a36b36278fdfce..ddf32a6bc415c28f0b9639514dd86eb11b18ce85 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -386,7 +386,7 @@ 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;
@@ -423,6 +423,7 @@ 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 876c6ca2d8f9e77a28f1e629aa6523df1ee8f42f..840cf1b9e6eee76cbf52c1ad85bdf16c84cf6d0b 100644 (file)
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -841,10 +841,11 @@ 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 5cb8ddb505ee8911461ec92a5c74feef0b441e00..23c3e5b5bb53f9e6f40ebbe8de4afd1683f9d7e5 100644 (file)
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -697,7 +697,7 @@ 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 5944d7d668dd91da21e945eac748bbbbbb11d67a..44dfaa09b58400ee3def792f0d366caf8dfd4d9b 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1236,7 +1236,7 @@ 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 a454b0ff57c7c67a91e2e5c887609e7a65e5a910..d690204a0275cd0d0f659e8efd15c3f3889c9184 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 8815e31a87fed4ba51ebd78a6724df8a3a436b85..a83243c3d656f553b6ccec94451e26e28cd1e743 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 e24ff1df0401288e4e810cf79ec3ea20d86a06c0..7fb4e14c467f60b4a65236b04fda13c6b5b9107d 100644 (file)
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -466,10 +466,10 @@ 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 81eb8cf8389b6a5af55f7b2994d7dbefe3d732bf..bcd5699313c38139306d06f733cb1ba130a1503c 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -393,10 +393,10 @@ 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 cfd65304be60ae8937449a8c1e4cf77406c11305..d9b437e5500795219339c85a8aab8a0301cc77b9 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)