From: jooseong lee <jooseong.lee@samsung.com>
Date: Wed, 20 Jul 2016 01:07:11 +0000 (+0900)
Subject: Smack: Assign smack_known_web label for kernel thread's socket in the sk_alloc_securi... 
X-Git-Tag: submit/tizen/20160721.001709~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=aa404a01f55b1d2cea9c4fd5a1c7ecba99f80b94;p=platform%2Fkernel%2Flinux-exynos.git

Smack: Assign smack_known_web label for kernel thread's socket in the sk_alloc_security hook

Creating struct sock by sk_alloc function in various kernel subsystems
like bluetooth dosen't call smack_socket_post_create(). In such case,
received sock label is the floor('_') label and makes access deny.

Refers to:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7412301b76bd53ee53b860f611fc3b5b1c2245b5

Change-Id: I614c5f0e6d59be5ca6b49f0581edfef79fc334cf
Signed-off-by: jooseong lee <jooseong.lee@samsung.com>
---

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 8e6c1e3dba5e..793c23a43b4f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2344,8 +2344,16 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
 	if (ssp == NULL)
 		return -ENOMEM;
 
-	ssp->smk_in = skp;
-	ssp->smk_out = skp;
+	/*
+	 * Sockets created by kernel threads receive web label.
+	 */
+	if (unlikely(current->flags & PF_KTHREAD)) {
+		ssp->smk_in = &smack_known_web;
+		ssp->smk_out = &smack_known_web;
+	} else {
+		ssp->smk_in = skp;
+		ssp->smk_out = skp;
+	}
 	ssp->smk_packet = NULL;
 
 	sk->sk_security = ssp;