smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity()

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>

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 72b371812a001b5ac10bb1b8d851a7a30c3a8ad2..6e5f74813c1018d752f5236f7cb6cc8462ccff48 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2856,6 +2856,15 @@ 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);