Replace the secid value stored in struct audit_context with a struct
lsmblob. Change the code that uses this value to accommodate the
change. security_audit_rule_match() expects a lsmblob, so existing
scaffolding can be removed. A call to security_secid_to_secctx()
is changed to security_lsmblob_to_secctx(). The call to
security_ipc_getsecid() is scaffolded.
A new function lsmblob_is_set() is introduced to identify whether
an lsmblob contains a non-zero value.
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
include/linux/security.h | 13 +++++++++++++
kernel/audit.h | 3 ++-
kernel/auditsc.c | 19 ++++++++-----------
3 files changed, 23 insertions(+), 12 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 457fafc32fb0..a0b23b6e8734 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -277,6 +277,19 @@ static inline const char *kernel_load_data_id_str(enum kernel_load_data_id id)
return kernel_load_data_str[id];
}
+/**
+ * lsmblob_is_set - report if there is a value in the lsmblob
+ * @blob: Pointer to the exported LSM data
+ *
+ * Returns true if there is a value set, false otherwise
+ */
+static inline bool lsmblob_is_set(struct lsmblob *blob)
+{
+ const struct lsmblob empty = {};
+
+ return !!memcmp(blob, &empty, sizeof(*blob));
+}
+
#ifdef CONFIG_SECURITY
int call_blocking_lsm_notifier(enum lsm_event event, void *data);
diff --git a/kernel/audit.h b/kernel/audit.h
index a60d2840559e..b1f2de4d4f1e 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -11,6 +11,7 @@
#include <linux/fs.h>
#include <linux/audit.h>
+#include <linux/security.h>
#include <linux/skbuff.h>
#include <uapi/linux/mqueue.h>
#include <linux/tty.h>
@@ -160,7 +161,7 @@ struct audit_context {
kuid_t uid;
kgid_t gid;
umode_t mode;
- u32 osid;
+ struct lsmblob oblob;
int has_perm;
uid_t perm_uid;
gid_t perm_gid;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 23adb15cae43..84f6e9356b8f 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -724,9 +724,7 @@ static int audit_filter_rules(struct task_struct *tsk,
/* Find ipc objects that match */
if (!ctx || ctx->type != AUDIT_IPC)
break;
- /* scaffolding */
- blob.scaffold.secid = ctx->ipc.osid;
- if (security_audit_rule_match(&blob,
+ if (security_audit_rule_match(&ctx->ipc.oblob,
f->type, f->op,
f->lsm_rule))
++result;
@@ -1394,19 +1392,17 @@ static void show_special(struct audit_context *context, int *call_panic)
audit_log_format(ab, " a%d=%lx", i,
context->socketcall.args[i]);
break; }
- case AUDIT_IPC: {
- u32 osid = context->ipc.osid;
-
+ case AUDIT_IPC:
audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho",
from_kuid(&init_user_ns, context->ipc.uid),
from_kgid(&init_user_ns, context->ipc.gid),
context->ipc.mode);
- if (osid) {
+ if (lsmblob_is_set(&context->ipc.oblob)) {
char *ctx = NULL;
u32 len;
- if (security_secid_to_secctx(osid, &ctx, &len)) {
- audit_log_format(ab, " osid=%u", osid);
+ if (security_lsmblob_to_secctx(&context->ipc.oblob,
+ &ctx, &len)) {
*call_panic = 1;
} else {
audit_log_format(ab, " obj=%s", ctx);
@@ -1426,7 +1422,7 @@ static void show_special(struct audit_context *context, int *call_panic)
context->ipc.perm_gid,
context->ipc.perm_mode);
}
- break; }
+ break;
case AUDIT_MQ_OPEN:
audit_log_format(ab,
"oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld "
@@ -2642,7 +2638,8 @@ void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
context->ipc.gid = ipcp->gid;
context->ipc.mode = ipcp->mode;
context->ipc.has_perm = 0;
- security_ipc_getsecid(ipcp, &context->ipc.osid);
+ /* scaffolding */
+ security_ipc_getsecid(ipcp, &context->ipc.oblob.scaffold.secid);
context->type = AUDIT_IPC;
}
--
2.46.0
