4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal <fw@xxxxxxxxx> [ Upstream commit 86126b77dcd551ce223e7293bb55854e3df05646 ] nlmsg_multicast() always frees the skb, so in case we cannot call it we must do that ourselves. Fixes: 21ee543edc0dea ("xfrm: fix race between netns cleanup and state expire notification") Signed-off-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/xfrm/xfrm_user.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -984,10 +984,12 @@ static inline int xfrm_nlmsg_multicast(s { struct sock *nlsk = rcu_dereference(net->xfrm.nlsk); - if (nlsk) - return nlmsg_multicast(nlsk, skb, pid, group, GFP_ATOMIC); - else - return -1; + if (!nlsk) { + kfree_skb(skb); + return -EPIPE; + } + + return nlmsg_multicast(nlsk, skb, pid, group, GFP_ATOMIC); } static inline size_t xfrm_spdinfo_msgsize(void)