[v2.6.34-stable 032/213] ipvs: fix info leak in getsockopt(IP_VS_SO_GET_TIMEOUT)

[Paul Gortmaker]

From: Mathias Krause <minipli@xxxxxxxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 2d8a041b7bfe1097af21441cb77d6af95f4f4680 upstream.

If at least one of CONFIG_IP_VS_PROTO_TCP or CONFIG_IP_VS_PROTO_UDP is
not set, __ip_vs_get_timeouts() does not fully initialize the structure
that gets copied to userland and that for leaks up to 12 bytes of kernel
stack. Add an explicit memset(0) before passing the structure to
__ip_vs_get_timeouts() to avoid the info leak.

Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Cc: Wensong Zhang <wensong@xxxxxxxxxxxx>
Cc: Simon Horman <horms@xxxxxxxxxxxx>
Cc: Julian Anastasov <ja@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 net/netfilter/ipvs/ip_vs_ctl.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 36dc1d88c2fa..bd9d805a85a6 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -2469,6 +2469,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
 	{
 		struct ip_vs_timeout_user t;
 
+		memset(&t, 0, sizeof(t));
 		__ip_vs_get_timeouts(&t);
 		if (copy_to_user(user, &t, sizeof(t)) != 0)
 			ret = -EFAULT;
-- 
1.8.5.2

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