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authorDan Carpenter <dan.carpenter@oracle.com>2013-10-03 00:27:20 +0300
committerDavid S. Miller <davem@davemloft.net>2013-10-03 16:05:14 -0400
commit1661bf364ae9c506bc8795fef70d1532931be1e8 (patch)
tree2ce62724a9931016cbbdb1bb94bc140012524c71 /net
parent196896d4bb297e3ff24e62b2bfc22bbed7a28431 (diff)
downloadlwn-1661bf364ae9c506bc8795fef70d1532931be1e8.tar.gz
lwn-1661bf364ae9c506bc8795fef70d1532931be1e8.zip
net: heap overflow in __audit_sockaddr()
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.aedla@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/compat.c2
-rw-r--r--net/socket.c24
2 files changed, 22 insertions, 4 deletions
diff --git a/net/compat.c b/net/compat.c
index f0a1ba6c8086..89032580bd1d 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -71,6 +71,8 @@ int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
__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);
diff --git a/net/socket.c b/net/socket.c
index ebed4b68f768..c226aceee65b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1964,6 +1964,16 @@ 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)
@@ -1982,8 +1992,11 @@ static int ___sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
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;
@@ -2191,8 +2204,11 @@ static int ___sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
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;