apparmor: prepare to support newer versions of policy

Newer policy encodes more than just version in the version tag,
so add masking to make sure the comparison remains correct.

Note: this is fully compatible with older policy as it will never set
the bits being masked out.

Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
John Johansen 2017-01-16 00:42:39 -08:00
parent 5ebfb12822
commit 474d6b7510
2 changed files with 25 additions and 10 deletions

View File

@ -799,9 +799,15 @@ static struct aa_fs_entry aa_fs_entry_domain[] = {
{ }
};
static struct aa_fs_entry aa_fs_entry_versions[] = {
AA_FS_FILE_BOOLEAN("v5", 1),
{ }
};
static struct aa_fs_entry aa_fs_entry_policy[] = {
AA_FS_FILE_BOOLEAN("set_load", 1),
{}
AA_FS_DIR("versions", aa_fs_entry_versions),
AA_FS_FILE_BOOLEAN("set_load", 1),
{ }
};
static struct aa_fs_entry aa_fs_entry_features[] = {

View File

@ -29,7 +29,14 @@
#include "include/policy.h"
#include "include/policy_unpack.h"
#define K_ABI_MASK 0x3ff
#define FORCE_COMPLAIN_FLAG 0x800
#define VERSION_LT(X, Y) (((X) & K_ABI_MASK) < ((Y) & K_ABI_MASK))
#define VERSION_GT(X, Y) (((X) & K_ABI_MASK) > ((Y) & K_ABI_MASK))
#define v5 5 /* base version */
#define v6 6 /* per entry policydb mediation check */
#define v7 7 /* full network masking */
/*
* The AppArmor interface treats data as a type byte followed by the
@ -646,19 +653,21 @@ static int verify_header(struct aa_ext *e, int required, const char **ns)
/* get the interface version */
if (!unpack_u32(e, &e->version, "version")) {
if (required) {
audit_iface(NULL, NULL, "invalid profile format", e,
error);
return error;
}
/* check that the interface version is currently supported */
if (e->version != 5) {
audit_iface(NULL, NULL, "unsupported interface version",
audit_iface(NULL, NULL, "invalid profile format",
e, error);
return error;
}
}
/* Check that the interface version is currently supported.
* if not specified use previous version
* Mask off everything that is not kernel abi version
*/
if (VERSION_LT(e->version, v5) && VERSION_GT(e->version, v7)) {
audit_iface(NULL, NULL, "unsupported interface version",
e, error);
return error;
}
/* read the namespace if present */
if (unpack_str(e, &name, "namespace")) {