smack: Add a new '-CIPSO' option to the network address label configuration
This patch adds a new special option '-CIPSO' to the Smack subsystem. When used
in the netlabel list, it means "use CIPSO networking". A use case is when your
local network speaks CIPSO and you want also to connect to the unlabeled
Internet. This patch also add some documentation describing that. The patch
also corrects an oops when setting a '' SMACK64 xattr to a file.
Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Signed-off-by: Paul Moore <paul.moore@hp.com>
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 8ed502c..9215149 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -609,6 +609,9 @@
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] == '-'))
+ rc = -EINVAL;
} else
rc = cap_inode_setxattr(dentry, name, value, size, flags);
@@ -1323,8 +1326,12 @@
* so we have found the most specific match
*/
if ((&snp->smk_host.sin_addr)->s_addr ==
- (siap->s_addr & (&snp->smk_mask)->s_addr))
+ (siap->s_addr & (&snp->smk_mask)->s_addr)) {
+ /* we have found the special CIPSO option */
+ if (snp->smk_label == smack_cipso_option)
+ return NULL;
return snp->smk_label;
+ }
return NULL;
}
@@ -1486,7 +1493,7 @@
struct socket *sock;
int rc = 0;
- if (value == NULL || size > SMK_LABELLEN)
+ if (value == NULL || size > SMK_LABELLEN || size == 0)
return -EACCES;
sp = smk_import(value, size);
