[PATCH] ipv4/ip_sockglue.c: copy msg_control optval from user to kernel space

[H Hartley Sweeten]

ipv4/ip_sockglue.c: copy msg_control optval from user to kernel space

In do_ip_getsockopt the char __user *optval is used directly in
IP_PKTOPTIONS for the msg.msg_control and not copied from
user to kernel address space. This produces a sparse warning:

warning: incorrect type in assignment (different address spaces)
   expected void *msg_control
   got char [noderef] <asn:1>*optval

Fix this by using copy _from_user to set msg.msg_control.

Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Alexey Kuznetsov <kuznet@xxxxxxxxxxxxx>
Cc: "Pekka Savola (ipv6)" <pekkas@xxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: Hideaki YOSHIFUJI <yoshfuji@xxxxxxxxxxxxxx>
Cc: Patrick McHardy <kaber@xxxxxxxxx>

---

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index cafad9b..8065456 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1173,7 +1173,8 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 		if (sk->sk_type != SOCK_STREAM)
 			return -ENOPROTOOPT;
 
-		msg.msg_control = optval;
+		if (copy_from_user(msg.msg_control, optval, len))
+			return -EFAULT;
 		msg.msg_controllen = len;
 		msg.msg_flags = 0;
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/