[3.5.y.z extended stable] Patch "inet: prevent leakage of uninitialized memory to user in recv" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Tue Dec 10 14:27:57 UTC 2013


This is a note to let you know that I have just added a patch titled

    inet: prevent leakage of uninitialized memory to user in recv

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 66c735eb8b85d1191fee15c64342d537d067b864 Mon Sep 17 00:00:00 2001
From: Hannes Frederic Sowa <hannes at stressinduktion.org>
Date: Mon, 18 Nov 2013 04:20:45 +0100
Subject: inet: prevent leakage of uninitialized memory to user in recv
 syscalls

commit bceaa90240b6019ed73b49965eac7d167610be69 upstream.

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 <mpb.mail at gmail.com>
Suggested-by: Eric Dumazet <eric.dumazet at gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
[ luis: backported to 3.5: based on davem's backport to 3.4 ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 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 ++++-----
 7 files changed, 13 insertions(+), 29 deletions(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 79db4e5..ef0d19d 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -631,7 +631,6 @@ 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;

@@ -641,9 +640,6 @@ 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);

@@ -665,11 +661,14 @@ 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 0753bd7..16d075e 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -688,9 +688,6 @@ 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;
@@ -718,6 +715,7 @@ 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 cd45011..6579494 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1175,12 +1175,6 @@ 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);

@@ -1235,6 +1229,7 @@ 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 9dca4a8..07a7df6 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -457,9 +457,6 @@ 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);

@@ -499,6 +496,7 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,
 		sin6->sin6_scope_id = 0;
 		if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 			sin6->sin6_scope_id = 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 a006a21..a7364cd 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -348,9 +348,6 @@ 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);

@@ -423,7 +420,7 @@ try_again:
 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 				sin6->sin6_scope_id = 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 61d8b75..2bc35bc 100644
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -510,9 +510,6 @@ 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;
@@ -535,6 +532,7 @@ 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);
--
1.8.3.2





More information about the kernel-team mailing list