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[3.11,19/46] net: socket: error on a negative msg_namelen

Message ID 1397644322-13905-20-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques April 16, 2014, 10:31 a.m. UTC 
3.11.10.8 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Matthew Leach <matthew.leach@arm.com>

commit dbb490b96584d4e958533fb637f08b557f505657 upstream.

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: Luis Henriques <luis.henriques@canonical.com>
---
 net/socket.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox

Patch

diff --git a/net/socket.c b/net/socket.c
index 03d5324..6bfb9e4 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1981,6 +1981,10 @@  static int copy_msghdr_from_user(struct msghdr *kmsg,
 {
 	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;