[PATCH 4.9 065/104] netfilter: nfnetlink_queue: fix secctx memory leak

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Liping Zhang <zlpnob...@gmail.com>


[ Upstream commit 77c1c03c5b8ef28e55bb0aff29b1e006037ca645 ]

We must call security_release_secctx to free the memory returned by
security_secid_to_secctx, otherwise memory may be leaked forever.

Fixes: ef493bd930ae ("netfilter: nfnetlink_queue: add security context 
information")
Signed-off-by: Liping Zhang <zlpnob...@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 net/netfilter/nfnetlink_queue.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -443,7 +443,7 @@ nfqnl_build_packet_message(struct net *n
        skb = alloc_skb(size, GFP_ATOMIC);
        if (!skb) {
                skb_tx_error(entskb);
-               return NULL;
+               goto nlmsg_failure;
        }
 
        nlh = nlmsg_put(skb, 0, 0,
@@ -452,7 +452,7 @@ nfqnl_build_packet_message(struct net *n
        if (!nlh) {
                skb_tx_error(entskb);
                kfree_skb(skb);
-               return NULL;
+               goto nlmsg_failure;
        }
        nfmsg = nlmsg_data(nlh);
        nfmsg->nfgen_family = entry->state.pf;
@@ -598,12 +598,17 @@ nfqnl_build_packet_message(struct net *n
        }
 
        nlh->nlmsg_len = skb->len;
+       if (seclen)
+               security_release_secctx(secdata, seclen);
        return skb;
 
 nla_put_failure:
        skb_tx_error(entskb);
        kfree_skb(skb);
        net_err_ratelimited("nf_queue: error creating packet message\n");
+nlmsg_failure:
+       if (seclen)
+               security_release_secctx(secdata, seclen);
        return NULL;
 }