From a2214488937a84d8d0b5a3b546f97b2485029a17 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Mon, 18 Nov 2013 04:20:45 +0100 Subject: [PATCH] inet: prevent leakage of uninitialized memory to user in recv syscalls [ Upstream commit bceaa90240b6019ed73b49965eac7d167610be69 ] Only update *addr_len when we actually fill in sockaddr, otherwise we can return uninitialized memory from the stack to the caller in the recvfrom, recvmmsg and recvmsg syscalls. Drop the the (addr_len == NULL) checks because we only get called with a valid addr_len pointer either from sock_common_recvmsg or inet_recvmsg. If a blocking read waits on a socket which is concurrently shut down we now return zero and set msg_msgnamelen to 0. Reported-by: mpb Suggested-by: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ieee802154/dgram.c | 3 +-- net/ipv4/ping.c | 9 ++++----- net/ipv4/raw.c | 4 +--- net/ipv4/udp.c | 7 +------ net/ipv6/raw.c | 4 +--- net/ipv6/udp.c | 5 +---- net/l2tp/l2tp_ip.c | 4 +--- net/phonet/datagram.c | 9 ++++----- 8 files changed, 14 insertions(+), 31 deletions(-) diff --git a/net/ieee802154/dgram.c b/net/ieee802154/dgram.c index 581a595..1865fdf 100644 --- a/net/ieee802154/dgram.c +++ b/net/ieee802154/dgram.c @@ -315,9 +315,8 @@ static int dgram_recvmsg(struct kiocb *iocb, struct sock *sk, if (saddr) { saddr->family = AF_IEEE802154; saddr->addr = mac_cb(skb)->sa; - } - if (addr_len) *addr_len = sizeof(*saddr); + } if (flags & MSG_TRUNC) copied = skb->len; diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 7d93d62..be01d5b 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -626,7 +626,6 @@ static int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len, int noblock, int flags, int *addr_len) { struct inet_sock *isk = inet_sk(sk); - struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; struct sk_buff *skb; int copied, err; @@ -636,9 +635,6 @@ static int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, if (flags & MSG_OOB) goto out; - if (addr_len) - *addr_len = sizeof(*sin); - if (flags & MSG_ERRQUEUE) return ip_recv_error(sk, msg, len); @@ -660,11 +656,14 @@ static int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, sock_recv_timestamp(msg, sk, skb); /* Copy the address. */ - if (sin) { + if (msg->msg_name) { + struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; + sin->sin_family = AF_INET; sin->sin_port = 0 /* skb->h.uh->source */; sin->sin_addr.s_addr = ip_hdr(skb)->saddr; memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); } if (isk->cmsg_flags) ip_cmsg_recv(msg, skb); diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index 6fb2337..448e5a7 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -692,9 +692,6 @@ static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, if (flags & MSG_OOB) goto out; - if (addr_len) - *addr_len = sizeof(*sin); - if (flags & MSG_ERRQUEUE) { err = ip_recv_error(sk, msg, len); goto out; @@ -722,6 +719,7 @@ static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, sin->sin_addr.s_addr = ip_hdr(skb)->saddr; sin->sin_port = 0; memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); } if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 93b731d..eeb3474 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1207,12 +1207,6 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, int is_udplite = IS_UDPLITE(sk); bool slow; - /* - * Check any passed addresses - */ - if (addr_len) - *addr_len = sizeof(*sin); - if (flags & MSG_ERRQUEUE) return ip_recv_error(sk, msg, len); @@ -1274,6 +1268,7 @@ try_again: sin->sin_port = udp_hdr(skb)->source; sin->sin_addr.s_addr = ip_hdr(skb)->saddr; memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); } if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index eedff8c..d3c01a6 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -459,9 +459,6 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk, if (flags & MSG_OOB) return -EOPNOTSUPP; - if (addr_len) - *addr_len=sizeof(*sin6); - if (flags & MSG_ERRQUEUE) return ipv6_recv_error(sk, msg, len); @@ -500,6 +497,7 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk, sin6->sin6_flowinfo = 0; sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr, IP6CB(skb)->iif); + *addr_len = sizeof(*sin6); } sock_recv_ts_and_drops(msg, sk, skb); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index e7b28f9..f10f118 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -373,9 +373,6 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, int is_udp4; bool slow; - if (addr_len) - *addr_len = sizeof(struct sockaddr_in6); - if (flags & MSG_ERRQUEUE) return ipv6_recv_error(sk, msg, len); @@ -461,7 +458,7 @@ try_again: ipv6_iface_scope_id(&sin6->sin6_addr, IP6CB(skb)->iif); } - + *addr_len = sizeof(*sin6); } if (is_udp4) { if (inet->cmsg_flags) diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index 571db8d..da1a1ce 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -518,9 +518,6 @@ static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m if (flags & MSG_OOB) goto out; - if (addr_len) - *addr_len = sizeof(*sin); - skb = skb_recv_datagram(sk, flags, noblock, &err); if (!skb) goto out; @@ -543,6 +540,7 @@ static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m sin->sin_addr.s_addr = ip_hdr(skb)->saddr; sin->sin_port = 0; memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); + *addr_len = sizeof(*sin); } if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); diff --git a/net/phonet/datagram.c b/net/phonet/datagram.c index 12c30f3..38946b2 100644 --- a/net/phonet/datagram.c +++ b/net/phonet/datagram.c @@ -139,9 +139,6 @@ static int pn_recvmsg(struct kiocb *iocb, struct sock *sk, MSG_CMSG_COMPAT)) goto out_nofree; - if (addr_len) - *addr_len = sizeof(sa); - skb = skb_recv_datagram(sk, flags, noblock, &rval); if (skb == NULL) goto out_nofree; @@ -162,8 +159,10 @@ static int pn_recvmsg(struct kiocb *iocb, struct sock *sk, rval = (flags & MSG_TRUNC) ? skb->len : copylen; - if (msg->msg_name != NULL) - memcpy(msg->msg_name, &sa, sizeof(struct sockaddr_pn)); + if (msg->msg_name != NULL) { + memcpy(msg->msg_name, &sa, sizeof(sa)); + *addr_len = sizeof(sa); + } out: skb_free_datagram(sk, skb); -- 2.7.4