On 1/15/20 12:13 PM, KP Singh wrote:
From: KP Singh <kpsingh@xxxxxxxxxx>
- The list of hooks registered by an LSM is currently immutable as they
are declared with __lsm_ro_after_init and they are attached to a
security_hook_heads struct.
- For the BPF LSM we need to de/register the hooks at runtime. Making
the existing security_hook_heads mutable broadens an
attack vector, so a separate security_hook_heads is added for only
those that ~must~ be mutable.
- These mutable hooks are run only after all the static hooks have
successfully executed.
This is based on the ideas discussed in:
https://lore.kernel.org/lkml/20180408065916.GA2832@ircssh-2.c.rugged-nimbus-611.internal
Signed-off-by: KP Singh <kpsingh@xxxxxxxxxx>
---
[...]
diff --git a/security/security.c b/security/security.c
index cd2d18d2d279..4a2eb4c089b2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -652,20 +653,21 @@ static void __init lsm_early_task(struct task_struct *task)
\
hlist_for_each_entry(P, &security_hook_heads.FUNC, list) \
P->hook.FUNC(__VA_ARGS__); \
+ CALL_BPF_LSM_VOID_HOOKS(FUNC, __VA_ARGS__); \
} while (0)
-#define call_int_hook(FUNC, IRC, ...) ({ \
- int RC = IRC; \
- do { \
- struct security_hook_list *P; \
- \
+#define call_int_hook(FUNC, IRC, ...) ({ \
+ int RC = IRC; \
+ do { \
+ struct security_hook_list *P; \
hlist_for_each_entry(P, &security_hook_heads.FUNC, list) { \
- RC = P->hook.FUNC(__VA_ARGS__); \
- if (RC != 0) \
- break; \
- } \
- } while (0); \
- RC; \
+ RC = P->hook.FUNC(__VA_ARGS__); \
+ if (RC != 0) \
+ break; \
+ } \
+ RC = CALL_BPF_LSM_INT_HOOKS(RC, FUNC, __VA_ARGS__); \
Let's not clobber the return code from the other LSMs with the bpf one.
+ } while (0); \
+ RC; \
})
/* Security operations */
