Karmic SRU, CVE-2010-3859

[Tim Gardner]

The following changes since commit 8f57f1af10280643dcfda5da7233be6bc211dad5:
  Tim Gardner (1):
        Karmic SRU: thinkpad-acpi: lock down video output state access, CVE-2010-3448

are available in the git repository at:

  git://kernel.ubuntu.com/rtg/ubuntu-karmic.git CVE-2010-3859

David S. Miller (1):
      net: Limit socket I/O iovec total length to INT_MAX., CVE-2010-3859

Linus Torvalds (1):
      net: Truncate recvfrom and sendto length to INT_MAX., CVE-2010-3859

 net/compat.c     |   10 ++++++----
 net/core/iovec.c |   15 +++++++--------
 net/socket.c     |    4 ++++
 3 files changed, 17 insertions(+), 12 deletions(-)

>From 6f26927146d324dacc6b62e7e45f7c1e9d957760 Mon Sep 17 00:00:00 2001
From: David S. Miller <davem at davemloft.net>
Date: Thu, 28 Oct 2010 11:41:55 -0700
Subject: [PATCH 1/2] net: Limit socket I/O iovec total length to INT_MAX., CVE-2010-3859

BugLink: http://bugs.launchpad.net/bugs/708839

CVE-2010-3859

commit 8acfe468b0384e834a303f08ebc4953d72fb690a upstream.
Backported as far as 2.6.23.26

This helps protect us from overflow issues down in the
individual protocol sendmsg/recvmsg handlers.  Once
we hit INT_MAX we truncate out the rest of the iovec
by setting the iov_len members to zero.

This works because:

1) For SOCK_STREAM and SOCK_SEQPACKET sockets, partial
   writes are allowed and the application will just continue
   with another write to send the rest of the data.

2) For datagram oriented sockets, where there must be a
   one-to-one correspondance between write() calls and
   packets on the wire, INT_MAX is going to be far larger
   than the packet size limit the protocol is going to
   check for and signal with -EMSGSIZE.

Based upon a patch by Linus Torvalds.

Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 net/compat.c     |   10 ++++++----
 net/core/iovec.c |   15 +++++++--------
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/net/compat.c b/net/compat.c
index 8d73905..2a2659b 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -40,10 +40,12 @@ static inline int iov_from_user_compat_to_kern(struct iovec *kiov,
 		compat_size_t len;
 
 		if (get_user(len, &uiov32->iov_len) ||
-		   get_user(buf, &uiov32->iov_base)) {
-			tot_len = -EFAULT;
-			break;
-		}
+		    get_user(buf, &uiov32->iov_base))
+			return -EFAULT;
+
+		if (len > INT_MAX - tot_len)
+			len = INT_MAX - tot_len;
+
 		tot_len += len;
 		kiov->iov_base = compat_ptr(buf);
 		kiov->iov_len = (__kernel_size_t) len;
diff --git a/net/core/iovec.c b/net/core/iovec.c
index 16ad45d..b6a4780 100644
--- a/net/core/iovec.c
+++ b/net/core/iovec.c
@@ -60,14 +60,13 @@ int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr *address,
 	err = 0;
 
 	for (ct = 0; ct < m->msg_iovlen; ct++) {
-		err += iov[ct].iov_len;
-		/*
-		 * Goal is not to verify user data, but to prevent returning
-		 * negative value, which is interpreted as errno.
-		 * Overflow is still possible, but it is harmless.
-		 */
-		if (err < 0)
-			return -EMSGSIZE;
+		size_t len = iov[ct].iov_len;
+
+		if (len > INT_MAX - err) {
+			len = INT_MAX - err;
+			iov[ct].iov_len = len;
+		}
+		err += len;
 	}
 
 	return err;
-- 
1.7.0.4


>From 4dfb111df63ac2052d16928614829170393c446b Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds at linux-foundation.org>
Date: Sat, 30 Oct 2010 16:43:10 -0700
Subject: [PATCH 2/2] net: Truncate recvfrom and sendto length to INT_MAX., CVE-2010-3859

BugLink: http://bugs/launchpad.net/bugs/708839

CVE-2010-3859

commit 253eacc070b114c2ec1f81b067d2fed7305467b0 upstream.

Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 net/socket.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/net/socket.c b/net/socket.c
index 6d47165..f0dcc29 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1673,6 +1673,8 @@ SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
 	struct iovec iov;
 	int fput_needed;
 
+	if (len > INT_MAX)
+		len = INT_MAX;
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
 	if (!sock)
 		goto out;
@@ -1730,6 +1732,8 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
 	int err, err2;
 	int fput_needed;
 
+	if (size > INT_MAX)
+		size = INT_MAX;
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
 	if (!sock)
 		goto out;
-- 
1.7.0.4