[PATCH 3.5 017/103] inet: fix addr_len/msg->msg_namelen assignment in recv_error and rxpmtu functions

From: Luis Henriques
Date: Tue Dec 17 2013 - 13:14:20 EST


3.5.7.28 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>

commit 85fbaa75037d0b6b786ff18658ddf0b4014ce2a4 upstream.

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@xxxxxxxxxxxxxx>
Reported-by: Tom Labanowski
Cc: mpb <mpb.mail@xxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[ luis: backported to 3.5: based on davem's backport to 3.4 ]
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
include/net/ip.h | 2 +-
include/net/ipv6.h | 6 ++++--
net/ipv4/ip_sockglue.c | 3 ++-
net/ipv4/ping.c | 2 +-
net/ipv4/raw.c | 2 +-
net/ipv4/udp.c | 2 +-
net/ipv6/datagram.c | 7 +++++--
net/ipv6/raw.c | 4 ++--
net/ipv6/udp.c | 4 ++--
net/l2tp/l2tp_ip6.c | 2 +-
10 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h
index d34f531..9fd963f 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -446,7 +446,7 @@ 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 c11fa5d..94cb787 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -605,8 +605,10 @@ 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 aabeb7b..34790df 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -367,7 +367,7 @@ 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;
@@ -404,6 +404,7 @@ 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 ef0d19d..7207980 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -641,7 +641,7 @@ 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 16d075e..e9c21f7 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -689,7 +689,7 @@ 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 6579494..de3033a 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1176,7 +1176,7 @@ 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 be2b67d6..876739f 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -317,7 +317,7 @@ 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;
@@ -368,6 +368,7 @@ 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));
@@ -421,7 +422,8 @@ 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;
@@ -455,6 +457,7 @@ 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 07a7df6..dbd6795 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -458,10 +458,10 @@ 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 a7364cd..0a56096 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -349,10 +349,10 @@ 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 2c9ccce..c466f04 100644
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -659,7 +659,7 @@ 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)
--
1.8.3.2

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