From: Łukasz Stelmach <l.stelmach@samsung.com>
Date: Tue, 16 Dec 2014 15:53:08 +0000 (+0100)
Subject: smack: introduce a special case for tmpfs in smack_d_instantiate()
X-Git-Tag: submit/tizen_common/20151126.162616~12
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e1223282b3ef67848d616d3b6d39bf8a276a51a6;p=sdk%2Femulator%2Femulator-kernel.git

smack: introduce a special case for tmpfs in smack_d_instantiate()

Files created with __shmem_file_stup() appear to have somewhat fake
dentries which make them look like root directories and not get
the label the current process or ("*") star meant for tmpfs files.

Change-Id: I05c13597e8a26524a7b0c3a3686f64d4ff71deaf
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 3f2a50cbdddc..d90a3bccaaa6 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3037,7 +3037,8 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
 	 * of the superblock.
 	 */
 	if (opt_dentry->d_parent == opt_dentry) {
-		if (sbp->s_magic == CGROUP_SUPER_MAGIC) {
+		switch (sbp->s_magic) {
+		case CGROUP_SUPER_MAGIC:
 			/*
 			 * The cgroup filesystem is never mounted,
 			 * so there's no opportunity to set the mount
@@ -3045,8 +3046,19 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
 			 */
 			sbsp->smk_root = &smack_known_star;
 			sbsp->smk_default = &smack_known_star;
+			isp->smk_inode = sbsp->smk_root;
+			break;
+		case TMPFS_MAGIC:
+			/*
+			 * What about shmem/tmpfs anonymous files with dentry
+			 * obtained from d_alloc_pseudo()?
+			 */
+			isp->smk_inode = smk_of_current();
+			break;
+		default:
+			isp->smk_inode = sbsp->smk_root;
+			break;
 		}
-		isp->smk_inode = sbsp->smk_root;
 		isp->smk_flags |= SMK_INODE_INSTANT;
 		goto unlockandout;
 	}