Hardy SRU, CVE-2010-3859

[Tim Gardner]

The following changes since commit 9085d9652a762dc247db5afa749b4c22a8280140:
  Tim Gardner (1):
        UBUNTU: xen unified block-device I/O interface back end can orphan devices, CVE-2010-3699

are available in the git repository at:

  git://kernel.ubuntu.com/rtg/ubuntu-hardy.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     |    6 ++++++
 3 files changed, 19 insertions(+), 12 deletions(-)

>From 59d4dcd44ef01ebe655d1fe2ee6b77707c3e038c 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 377e560..6d3eea3 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -39,10 +39,12 @@ 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 755c37f..7f1fb83 100644
--- a/net/core/iovec.c
+++ b/net/core/iovec.c
@@ -60,14 +60,13 @@ int verify_iovec(struct msghdr *m, struct iovec *iov, char *address, int mode)
 	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 437611151eec628016a62238e0b34c3b0bb3c12b 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.
Stable backported to 2.6.32.26

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 |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/net/socket.c b/net/socket.c
index 14ee367..0f00319 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1583,6 +1583,9 @@ asmlinkage long sys_sendto(int fd, void __user *buff, size_t len,
 	int fput_needed;
 	struct file *sock_file;
 
+	if (len > INT_MAX)
+		len = INT_MAX;
+
 	sock_file = fget_light(fd, &fput_needed);
 	err = -EBADF;
 	if (!sock_file)
@@ -1644,6 +1647,9 @@ asmlinkage long sys_recvfrom(int fd, void __user *ubuf, size_t size,
 	struct file *sock_file;
 	int fput_needed;
 
+	if (size > INT_MAX)
+		size = INT_MAX;
+
 	sock_file = fget_light(fd, &fput_needed);
 	err = -EBADF;
 	if (!sock_file)
-- 
1.7.0.4