netdev - [PATCH net-next 1/3] bpf: use skb_to_full_sk helper in bpf_skb_under

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <6240d4a6e0a810999c06b7dc169cccde98806897.1474586162.git.daniel@iogearbox.net>
Date:   Fri, 23 Sep 2016 01:28:35 +0200
From:   Daniel Borkmann <daniel@...earbox.net>
To:     davem@...emloft.net
Cc:     alexei.starovoitov@...il.com, netdev@...r.kernel.org,
        Daniel Borkmann <daniel@...earbox.net>
Subject: [PATCH net-next 1/3] bpf: use skb_to_full_sk helper in bpf_skb_under_cgroup

We need to use skb_to_full_sk() helper introduced in commit bd5eb35f16a9
("xfrm: take care of request sockets") as otherwise we miss tcp synack
messages, since ownership is on request socket and therefore it would
miss the sk_fullsock() check. Use skb_to_full_sk() as also done similarly
in the bpf_get_cgroup_classid() helper via 2309236c13fe ("cls_cgroup:
get sk_classid only from full sockets") fix to not let this fall through.

Fixes: 4a482f34afcc ("cgroup: bpf: Add bpf_skb_in_cgroup_proto")
Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
Acked-by: Alexei Starovoitov <ast@...nel.org>
---
 net/core/filter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 0920c2a..e5d9977 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2408,7 +2408,7 @@ BPF_CALL_3(bpf_skb_under_cgroup, struct sk_buff *, skb, struct bpf_map *, map,
 	struct cgroup *cgrp;
 	struct sock *sk;
 
-	sk = skb->sk;
+	sk = skb_to_full_sk(skb);
 	if (!sk || !sk_fullsock(sk))
 		return -ENOENT;
 	if (unlikely(idx >= array->map.max_entries))
-- 
1.9.3