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authorCasey Schaufler <casey@schaufler-ca.com>2013-06-28 13:47:07 -0700
committerCasey Schaufler <casey@schaufler-ca.com>2013-08-01 20:04:02 -0700
commit677264e8fb73ea35a508700e19ce76c527576d1c (patch)
tree907b50534365824858c1df15dbfb4249c1079e4f /security
parent4d7cf4a1f49f76f4069114ee08be75cd68c37c5a (diff)
downloadlinux-677264e8fb73ea35a508700e19ce76c527576d1c.tar.gz
Smack: network label match fix
The Smack code that matches incoming CIPSO tags with Smack labels reaches through the NetLabel interfaces and compares the network data with the CIPSO header associated with a Smack label. This was done in a ill advised attempt to optimize performance. It works so long as the categories fit in a single capset, but this isn't always the case. This patch changes the Smack code to use the appropriate NetLabel interfaces to compare the incoming CIPSO header with the CIPSO header associated with a label. It will always match the CIPSO headers correctly. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Diffstat (limited to 'security')
-rw-r--r--security/smack/smack.h8
-rw-r--r--security/smack/smack_lsm.c30
-rw-r--r--security/smack/smackfs.c2
3 files changed, 31 insertions, 9 deletions
diff --git a/security/smack/smack.h b/security/smack/smack.h
index e80597a3048..076b8e8a51a 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -168,9 +168,13 @@ struct smk_port_label {
#define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */
#define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */
#define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */
-#define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */
#define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */
-#define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */
+/*
+ * CIPSO 2.2 standard is 239, but Smack wants to use the
+ * categories in a structured way that limits the value to
+ * the bits in 23 bytes, hence the unusual number.
+ */
+#define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */
/*
* Flag for transmute access
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index ce000a81caf..19204e11c02 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3066,6 +3066,8 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
{
struct smack_known *skp;
int found = 0;
+ int acat;
+ int kcat;
if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
/*
@@ -3082,12 +3084,28 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
list_for_each_entry(skp, &smack_known_list, list) {
if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
continue;
- if (memcmp(sap->attr.mls.cat,
- skp->smk_netlabel.attr.mls.cat,
- SMK_CIPSOLEN) != 0)
- continue;
- found = 1;
- break;
+ /*
+ * Compare the catsets. Use the netlbl APIs.
+ */
+ if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
+ if ((skp->smk_netlabel.flags &
+ NETLBL_SECATTR_MLS_CAT) == 0)
+ found = 1;
+ break;
+ }
+ for (acat = -1, kcat = -1; acat == kcat; ) {
+ acat = netlbl_secattr_catmap_walk(
+ sap->attr.mls.cat, acat + 1);
+ kcat = netlbl_secattr_catmap_walk(
+ skp->smk_netlabel.attr.mls.cat,
+ kcat + 1);
+ if (acat < 0 || kcat < 0)
+ break;
+ }
+ if (acat == kcat) {
+ found = 1;
+ break;
+ }
}
rcu_read_unlock();
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 269b270c647..a07e93f00a0 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -890,7 +890,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
for (i = 0; i < catlen; i++) {
rule += SMK_DIGITLEN;
ret = sscanf(rule, "%u", &cat);
- if (ret != 1 || cat > SMACK_CIPSO_MAXCATVAL)
+ if (ret != 1 || cat > SMACK_CIPSO_MAXCATNUM)
goto out;
smack_catset_bit(cat, mapcatset);