smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity()

[ Upstream commit ac02f007d64eb2769d0bde742aac4d7a5fc6e8a5 ]

If the SMACK64TRANSMUTE xattr is provided, and the inode is a directory,
update the in-memory inode flags by setting SMK_INODE_TRANSMUTE.

Cc: stable@vger.kernel.org
Fixes: 5c6d1125f8db ("Smack: Transmute labels on specified directories") # v2.6.38.x
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index c45f0d61447c760270f1a6019c55bf0d260142f9..c6f211758f4e384319a5aff7c16a50d7fb05f009 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2721,6 +2721,15 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
        if (value == NULL || size > SMK_LONGLABEL || size == 0)
                return -EINVAL;
 
+       if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) {
+               if (!S_ISDIR(inode->i_mode) || size != TRANS_TRUE_SIZE ||
+                   strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
+                       return -EINVAL;
+
+               nsp->smk_flags |= SMK_INODE_TRANSMUTE;
+               return 0;
+       }
+
        skp = smk_import_entry(value, size);
        if (IS_ERR(skp))
                return PTR_ERR(skp);