[net-next RFC v2 1/9] net: Make cgroup sk data present when calling security_sk_(alloc/free)

[net-next RFC v2 1/9] net: Make cgroup sk data present when calling security_sk_(alloc/free)

[Sargun Dhillon]

This patch changes the order of allocations / calls to allocate the
sock_cgroup_data before calling security_sk_alloc. In addition, this
patch also reorders the deallocation when calling security_sk_free
so that LSMs can examine the cgroup that a particular sk belongs to.

Signed-off-by: Sarguun Dhillon <sargun@sargun.me>
---
 net/core/sock.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 51a7304..3f12f4d 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1333,6 +1333,7 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
 
 	if (sk != NULL) {
 		kmemcheck_annotate_bitfield(sk, flags);
+		cgroup_sk_alloc(&sk->sk_cgrp_data);
 
 		if (security_sk_alloc(sk, family, priority))
 			goto out_free;
@@ -1340,7 +1341,6 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
 		if (!try_module_get(prot->owner))
 			goto out_free_sec;
 		sk_tx_queue_clear(sk);
-		cgroup_sk_alloc(&sk->sk_cgrp_data);
 	}
 
 	return sk;
@@ -1348,6 +1348,7 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
 out_free_sec:
 	security_sk_free(sk);
 out_free:
+	cgroup_sk_free(&sk->sk_cgrp_data);
 	if (slab != NULL)
 		kmem_cache_free(slab, sk);
 	else
@@ -1363,8 +1364,8 @@ static void sk_prot_free(struct proto *prot, struct sock *sk)
 	owner = prot->owner;
 	slab = prot->slab;
 
-	cgroup_sk_free(&sk->sk_cgrp_data);
 	security_sk_free(sk);
+	cgroup_sk_free(&sk->sk_cgrp_data);
 	if (slab != NULL)
 		kmem_cache_free(slab, sk);
 	else
-- 
2.7.4