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| author | John Johansen <john.johansen@canonical.com> | 2021-02-03 01:35:12 -0800 |
|---|---|---|
| committer | John Johansen <john.johansen@canonical.com> | 2022-07-09 15:13:59 -0700 |
| commit | 5bfcbd22ee4e6ad5ae698518fadd0f03ea109537 (patch) | |
| tree | 6724a92839d6ab4b84e590ecf14a09911df81090 /security | |
| parent | d61c57fde81915c04b41982f66a159ccc014e799 (diff) | |
| download | linux-5bfcbd22ee4e6ad5ae698518fadd0f03ea109537.tar.gz linux-5bfcbd22ee4e6ad5ae698518fadd0f03ea109537.tar.bz2 linux-5bfcbd22ee4e6ad5ae698518fadd0f03ea109537.zip | |
apparmor: Enable tuning of policy paranoid load for embedded systems
AppArmor by default does an extensive check on loaded policy that
can take quite some time on limited resource systems. Allow
disabling this check for embedded systems where system images are
readonly and have checksumming making the need for the embedded
policy to be fully checked to be redundant.
Note: basic policy checks are still done.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/apparmor/Kconfig | 11 | ||||
| -rw-r--r-- | security/apparmor/lsm.c | 2 | ||||
| -rw-r--r-- | security/apparmor/policy_unpack.c | 4 |
3 files changed, 15 insertions, 2 deletions
diff --git a/security/apparmor/Kconfig b/security/apparmor/Kconfig index 4c34a28a2ddf..cb3496e00d8a 100644 --- a/security/apparmor/Kconfig +++ b/security/apparmor/Kconfig @@ -94,6 +94,17 @@ config SECURITY_APPARMOR_EXPORT_BINARY also increases policy load time. This option is required for checkpoint and restore support, and debugging of loaded policy. +config SECURITY_APPARMOR_PARANOID_LOAD + bool "Perform full verification of loaded policy" + depends on SECURITY_APPARMOR + default y + help + This options allows controlling whether apparmor does a full + verification of loaded policy. This should not be disabled + except for embedded systems where the image is read only, + includes policy, and has some form of integrity check. + Disabling the check will speed up policy loads. + config SECURITY_APPARMOR_KUNIT_TEST bool "Build KUnit tests for policy_unpack.c" if !KUNIT_ALL_TESTS depends on KUNIT=y && SECURITY_APPARMOR diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 84a4e63d922d..301c2bba4867 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1405,7 +1405,7 @@ module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR); * DEPRECATED: read only as strict checking of load is always done now * that none root users (user namespaces) can load policy. */ -bool aa_g_paranoid_load = true; +bool aa_g_paranoid_load = IS_ENABLED(CONFIG_SECURITY_PARANOID_LOAD); module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO); static int param_get_aaintbool(char *buffer, const struct kernel_param *kp); diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 31d2c2626ea5..55dca9e3af50 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -457,7 +457,9 @@ static struct aa_dfa *unpack_dfa(struct aa_ext *e) ((e->pos - e->start) & 7); size_t pad = ALIGN(sz, 8) - sz; int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) | - TO_ACCEPT2_FLAG(YYTD_DATA32) | DFA_FLAG_VERIFY_STATES; + TO_ACCEPT2_FLAG(YYTD_DATA32); + if (aa_g_paranoid_load) + flags |= DFA_FLAG_VERIFY_STATES; dfa = aa_dfa_unpack(blob + pad, size - pad, flags); if (IS_ERR(dfa)) |