selinux: fix memleak in security_read_state_kernel()

[ Upstream commit 73de1befcc53a7c68b0c5e76b9b5ac41c517760f ]

In this function, it directly returns the result of __security_read_policy
without freeing the allocated memory in *data, cause memory leak issue,
so free the memory if __security_read_policy failed.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index c4931bf..e8035e4 100644 (file)
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -4045,6 +4045,7 @@ int security_read_policy(struct selinux_state *state,
 int security_read_state_kernel(struct selinux_state *state,
                               void **data, size_t *len)
 {
+       int err;
        struct selinux_policy *policy;
 
        policy = rcu_dereference_protected(
@@ -4057,5 +4058,11 @@ int security_read_state_kernel(struct selinux_state *state,
        if (!*data)
                return -ENOMEM;
 
-       return __security_read_policy(policy, *data, len);
+       err = __security_read_policy(policy, *data, len);
+       if (err) {
+               vfree(*data);
+               *data = NULL;
+               *len = 0;
+       }
+       return err;
 }