[PATCH 3/6] xfrm_user: fix info leak in copy_to_user_policy()

[Mathias Krause]

The memory reserved to dump the xfrm policy includes multiple padding
bytes added by the compiler for alignment (padding bytes in struct
xfrm_selector and struct xfrm_userpolicy_info). Add an explicit
memset(0) before filling the buffer to avoid the heap info leak.

Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
---
 net/xfrm/xfrm_user.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index c1f15b5..7511427 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1318,6 +1318,7 @@ static void copy_from_user_policy(struct xfrm_policy *xp, struct xfrm_userpolicy
 
 static void copy_to_user_policy(struct xfrm_policy *xp, struct xfrm_userpolicy_info *p, int dir)
 {
+	memset(p, 0, sizeof(*p));
 	memcpy(&p->sel, &xp->selector, sizeof(p->sel));
 	memcpy(&p->lft, &xp->lft, sizeof(p->lft));
 	memcpy(&p->curlft, &xp->curlft, sizeof(p->curlft));
-- 
1.7.10.4

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