3.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Carpenter <dan.carpen...@oracle.com>
[ Upstream commit 1661bf364ae9c506bc8795fef70d1532931be1e8 ]
We need to cap ->msg_namelen or it leads to a buffer overflow when we
to the memcpy() in __audit_sockaddr(). It requires CAP_AUDIT_CONTROL to
exploit this bug.
The call tree is:
___sys_recvmsg()
move_addr_to_user()
audit_sockaddr()
__audit_sockaddr()
Reported-by: Jüri Aedla <juri.ae...@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
net/compat.c | 2 ++
net/socket.c | 24 ++++++++++++++++++++----
2 files changed, 22 insertions(+), 4 deletions(-)
--- a/net/compat.c
+++ b/net/compat.c
@@ -71,6 +71,8 @@ int get_compat_msghdr(struct msghdr *kms
__get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
__get_user(kmsg->msg_flags, &umsg->msg_flags))
return -EFAULT;
+ if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
+ return -EINVAL;
kmsg->msg_name = compat_ptr(tmp1);
kmsg->msg_iov = compat_ptr(tmp2);
kmsg->msg_control = compat_ptr(tmp3);
--- a/net/socket.c
+++ b/net/socket.c
@@ -1973,6 +1973,16 @@ struct used_address {
unsigned int name_len;
};
+static int copy_msghdr_from_user(struct msghdr *kmsg,
+ struct msghdr __user *umsg)
+{
+ if (copy_from_user(kmsg, umsg, sizeof(struct msghdr)))
+ return -EFAULT;
+ if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
+ return -EINVAL;
+ return 0;
+}
+
static int ___sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
struct msghdr *msg_sys, unsigned int flags,
struct used_address *used_address)
@@ -1991,8 +2001,11 @@ static int ___sys_sendmsg(struct socket
if (MSG_CMSG_COMPAT & flags) {
if (get_compat_msghdr(msg_sys, msg_compat))
return -EFAULT;
- } else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr)))
- return -EFAULT;
+ } else {
+ err = copy_msghdr_from_user(msg_sys, msg);
+ if (err)
+ return err;
+ }
if (msg_sys->msg_iovlen > UIO_FASTIOV) {
err = -EMSGSIZE;
@@ -2200,8 +2213,11 @@ static int ___sys_recvmsg(struct socket
if (MSG_CMSG_COMPAT & flags) {
if (get_compat_msghdr(msg_sys, msg_compat))
return -EFAULT;
- } else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr)))
- return -EFAULT;
+ } else {
+ err = copy_msghdr_from_user(msg_sys, msg);
+ if (err)
+ return err;
+ }
if (msg_sys->msg_iovlen > UIO_FASTIOV) {
err = -EMSGSIZE;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
