net: socket: error on a negative msg_namelen
[ Upstream commit dbb490b96584d4e958533fb637f08b557f505657 ]
When copying in a struct msghdr from the user, if the user has set the
msg_namelen parameter to a negative value it gets clamped to a valid
size due to a comparison between signed and unsigned values.
Ensure the syscall errors when the user passes in a negative value.
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/socket.c b/net/socket.c
index 6f55988..96a902d 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1932,6 +1932,10 @@
{
if (copy_from_user(kmsg, umsg, sizeof(struct msghdr)))
return -EFAULT;
+
+ if (kmsg->msg_namelen < 0)
+ return -EINVAL;
+
if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
kmsg->msg_namelen = sizeof(struct sockaddr_storage);
return 0;