ipvs: fix info leak in getsockopt(IP_VS_SO_GET_TIMEOUT)

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@googlemail.com>
Cc: Wensong Zhang <wensong@linux-vs.org>
Cc: Simon Horman <horms@verge.net.au>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 2.6.32: adjust context]
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 02b2610c4d2e88acd378f7305de45f2bd427d3ae..9bcd9725ddef06bb2af07bbdfea880fdc1973a4c 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -2455,6 +2455,7 @@ 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;