| From | Jiri Slaby <> | Subject | [PATCH 3.12 42/72] net: socket: error on a negative msg_namelen | Date | Fri, 18 Apr 2014 11:22:15 +0200 |
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From: Matthew Leach <matthew.leach@arm.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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[ 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: Jiri Slaby <jslaby@suse.cz> --- net/socket.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/net/socket.c b/net/socket.c index e83c416708af..dc57dae20a9a 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1972,6 +1972,10 @@ 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; -- 1.9.2
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