apparmor: convert xmatch lookup to use accept as an index

Remap xmatch dfa accept table from embedded perms to an index and then
move xmatch lookup to use accept entry to index into the xmatch table.

This is step towards unifying permission lookup and reducing the
size of permissions tables.

Signed-off-by: John Johansen <john.johansen@canonical.com>

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 0df17fb..45a8887 100644 (file)
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -328,7 +328,7 @@ static int aa_xattrs_match(const struct linux_binprm *bprm,
                size = vfs_getxattr_alloc(&init_user_ns, d, profile->xattrs[i],
                                          &value, value_size, GFP_KERNEL);
                if (size >= 0) {
-                       u32 perm;
+                       u32 index, perm;
 
                        /*
                         * Check the xattr presence before value. This ensure
@@ -340,7 +340,8 @@ static int aa_xattrs_match(const struct linux_binprm *bprm,
                        /* Check xattr value */
                        state = aa_dfa_match_len(profile->xmatch.dfa, state,
                                                 value, size);
-                       perm = profile->xmatch.perms[state].allow;
+                       index = ACCEPT_TABLE(profile->xmatch.dfa)[state];
+                       perm = profile->xmatch.perms[index].allow;
                        if (!(perm & MAY_EXEC)) {
                                ret = -EINVAL;
                                goto out;
@@ -416,12 +417,13 @@ restart:
                 */
                if (profile->xmatch.dfa) {
                        unsigned int state, count;
-                       u32 perm;
+                       u32 index, perm;
 
                        state = aa_dfa_leftmatch(profile->xmatch.dfa,
                                        profile->xmatch.start[AA_CLASS_XMATCH],
                                        name, &count);
-                       perm = profile->xmatch.perms[state].allow;
+                       index = ACCEPT_TABLE(profile->xmatch.dfa)[state];
+                       perm = profile->xmatch.perms[index].allow;
                        /* any accepting state means a valid match. */
                        if (perm & MAY_EXEC) {
                                int ret = 0;

diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index 4cf62c1..4cdc969 100644 (file)
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -930,6 +930,7 @@ static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
                        info = "failed to convert xmatch permission table";
                        goto fail;
                }
+               remap_dfa_accept(profile->xmatch.dfa, 1);
        }
 
        /* disconnected attachment string is optional */