Smack: check for SMACK xattr validity in smack_inode_setxattr
the following patch moves checks for SMACK xattr validity
from smack_inode_post_setxattr (which cannot return an error to the user)
to smack_inode_setxattr (which can return an error).
Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 9215149..98b3195 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -609,8 +609,12 @@
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
if (!capable(CAP_MAC_ADMIN))
rc = -EPERM;
- /* a label cannot be void and cannot begin with '-' */
- if (size == 0 || (size > 0 && ((char *)value)[0] == '-'))
+ /*
+ * check label validity here so import wont fail on
+ * post_setxattr
+ */
+ if (size == 0 || size >= SMK_LABELLEN ||
+ smk_import(value, size) == NULL)
rc = -EINVAL;
} else
rc = cap_inode_setxattr(dentry, name, value, size, flags);
@@ -644,9 +648,6 @@
if (strcmp(name, XATTR_NAME_SMACK))
return;
- if (size >= SMK_LABELLEN)
- return;
-
isp = dentry->d_inode->i_security;
/*