Commit dbb490b9 authored Mar 11, 2014 by Matthew Leach Committed by David S. Miller Mar 12, 2014

net: socket: error on a negative msg_namelen

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>

parent 7e814a6c

net/socket.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1985,6 +1985,10 @@ 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;

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