Re: linux-next: Tree for Jul 24 (apparmor)

From: John Johansen
Date: Mon Jul 25 2016 - 14:00:51 EST


On 07/24/2016 04:26 PM, Randy Dunlap wrote:
> On 07/24/16 01:20, Stephen Rothwell wrote:
>> Hi all,
>>
>> Changes since 20160722:
>>
>
> on x86_64:
>
> CONFIG_SECURITY_APPARMOR=y
> CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE=1
> # CONFIG_SECURITY_APPARMOR_HASH is not set
>
> ../security/apparmor/lsm.c:675:25: error: 'CONFIG_SECURITY_APPARMOR_HASH_DEFAULT' undeclared here (not in a function)
> bool aa_g_hash_policy = CONFIG_SECURITY_APPARMOR_HASH_DEFAULT;
> ^
>
>
yep thanks, its fixed by the following patch, and I have requested James pull it



The newly added Kconfig option could never work and just causes a build error
when disabled:

security/apparmor/lsm.c:675:25: error: 'CONFIG_SECURITY_APPARMOR_HASH_DEFAULT' undeclared here (not in a function)
bool aa_g_hash_policy = CONFIG_SECURITY_APPARMOR_HASH_DEFAULT;

The problem is that the macro undefined in this case, and we need to use the IS_ENABLED()
helper to turn it into a boolean constant.

Another minor problem with the original patch is that the option is even offered
in sysfs when SECURITY_APPARMOR_HASH is not enabled, so this also hides the option
in that case.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Fixes: 6059f71f1e94 ("apparmor: add parameter to control whether policy hashing is used")
---
security/apparmor/crypto.c | 3 +++
security/apparmor/lsm.c | 4 +++-
security/apparmor/policy_unpack.c | 3 +--
3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/security/apparmor/crypto.c b/security/apparmor/crypto.c
index 532471d0b3a0..b75dab0df1cb 100644
--- a/security/apparmor/crypto.c
+++ b/security/apparmor/crypto.c
@@ -39,6 +39,9 @@ int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start,
int error = -ENOMEM;
u32 le32_version = cpu_to_le32(version);

+ if (!aa_g_hash_policy)
+ return 0;
+
if (!apparmor_tfm)
return 0;

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 3be30c701bfa..41b8cb115801 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -671,9 +671,11 @@ enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
module_param_call(mode, param_set_mode, param_get_mode,
&aa_g_profile_mode, S_IRUSR | S_IWUSR);

+#ifdef CONFIG_SECURITY_APPARMOR_HASH
/* whether policy verification hashing is enabled */
-bool aa_g_hash_policy = CONFIG_SECURITY_APPARMOR_HASH_DEFAULT;
+bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
+#endif

/* Debug mode */
bool aa_g_debug;
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index b9b1c66a32a5..138120698f83 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -778,8 +778,7 @@ int aa_unpack(void *udata, size_t size, struct list_head *lh, const char **ns)
if (error)
goto fail_profile;

- if (aa_g_hash_policy)
- error = aa_calc_profile_hash(profile, e.version, start,
+ error = aa_calc_profile_hash(profile, e.version, start,
e.pos - start);
if (error)
goto fail_profile;
--
2.9.0