build_expire() clears the trailing padding bytes of struct xfrm_user_expire after setting the hard field via memset_after(), but the analogous function build_polexpire() does not do this for struct xfrm_user_polexpire. The 7 bytes of padding after the __u8 hard field are left uninitialized from the heap allocation, and are then sent to userspace via netlink multicast to XFRMNLGRP_EXPIRE listeners, leaking kernel heap memory contents. Add the missing memset_after() call, matching build_expire(). Signed-off-by: Yasuaki Torimaru --- net/xfrm/xfrm_user.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 403b5ecac..ee31ef482 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -3948,6 +3948,8 @@ static int build_polexpire(struct sk_buff *skb, struct xfrm_policy *xp, return err; } upe->hard = !!hard; + /* clear the padding bytes */ + memset_after(upe, 0, hard); nlmsg_end(skb, nlh); return 0; -- 2.50.1