[PATCH 3.12 32/83] inet: fix addr_len/msg->msg_namelen assignment in recv_error and rxpmtu functions

Greg Kroah-Hartman
2013-12-06T22:37:11Z

From: Hannes Frederic Sowa <hannes@stressinduktion.org>

[ 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>
---
include/net/ip.h | 2 +-
include/net/ipv6.h | 6 ++++--
include/net/ping.h | 3 ++-
net/ipv4/ip_sockglue.c | 3 ++-
net/ipv4/ping.c | 5 +++--
net/ipv4/raw.c | 2 +-
net/ipv4/udp.c | 2 +-
net/ipv6/datagram.c | 7 +++++--
net/ipv6/ping.c | 3 ++-
net/ipv6/raw.c | 4 ++--
net/ipv6/udp.c | 4 ++--
net/l2tp/l2tp_ip6.c | 2 +-
12 files changed, 26 insertions(+), 17 deletions(-)

--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -464,7 +464,7 @@ extern int compat_ip_getsockopt(struct s
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,
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -802,8 +802,10 @@ extern int compat_ipv6_getsockopt(stru
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);
--- 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);
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -368,7 +368,7 @@ void ip_local_error(struct sock *sk, int
/*
* 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, struc
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));
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -838,10 +838,11 @@ int ping_recvmsg(struct kiocb *iocb, str

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
}
}
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -695,7 +695,7 @@ static int raw_recvmsg(struct kiocb *ioc
goto out;

if (flags & MSG_ERRQUEUE) {
- err = ip_recv_error(sk, msg, len);
+ err = ip_recv_error(sk, msg, len, addr_len);
goto out;
}

--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1210,7 +1210,7 @@ int udp_recvmsg(struct kiocb *iocb, stru
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),
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -318,7 +318,7 @@ void ipv6_local_rxpmtu(struct sock *sk,
/*
* 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, str
&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, st
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);
--- a/net/ipv6/ping.c
+++ b/net/ipv6/ping.c
@@ -57,7 +57,8 @@ static struct inet_protosw pingv6_protos

/* 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;
}
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -467,10 +467,10 @@ static int rawv6_recvmsg(struct kiocb *i
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)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -375,10 +375,10 @@ int udpv6_recvmsg(struct kiocb *iocb, st
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),
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -665,7 +665,7 @@ static int l2tp_ip6_recvmsg(struct kiocb
*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)