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

H Hartley Sweeten
2010-01-15T17:25:06Z

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@visionengravers.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "Pekka Savola (ipv6)" <pekkas@netcore.fi>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>

---

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;