[PATCH v38 34/39] audit: multiple subject lsm values for netlabel

[Casey Schaufler]

Refactor audit_log_task_context(), creating a new
audit_log_subject_context(). This is used in netlabel auditing
to provide multiple subject security contexts as necessary.

Acked-by: Paul Moore <p...@paul-moore.com>
Signed-off-by: Casey Schaufler <ca...@schaufler-ca.com>
---
 include/linux/audit.h        |  7 +++++++
 kernel/audit.c               | 26 ++++++++++++++++----------
 net/netlabel/netlabel_user.c |  7 +------
 3 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index edb919722448..87ba6fe7f1a2 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -188,6 +188,8 @@ extern void             audit_log_path_denied(int type,
                                                  const char *operation);
 extern void                audit_log_lost(const char *message);
 
+extern int audit_log_subject_context(struct audit_buffer *ab,
+                                    struct lsmblob *blob);
 extern int audit_log_task_context(struct audit_buffer *ab);
 extern void audit_log_task_info(struct audit_buffer *ab);
 
@@ -248,6 +250,11 @@ static inline void audit_log_key(struct audit_buffer *ab, 
char *key)
 { }
 static inline void audit_log_path_denied(int type, const char *operation)
 { }
+static inline int audit_log_subject_context(struct audit_buffer *ab,
+                                           struct lsmblob *blob)
+{
+       return 0;
+}
 static inline int audit_log_task_context(struct audit_buffer *ab)
 {
        return 0;
diff --git a/kernel/audit.c b/kernel/audit.c
index fb182f7e9d18..a611130f83cb 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2226,20 +2226,17 @@ static void audit_buffer_aux_end(struct audit_buffer 
*ab)
        ab->skb = skb_peek(&ab->skb_list);
 }
 
-int audit_log_task_context(struct audit_buffer *ab)
+int audit_log_subject_context(struct audit_buffer *ab, struct lsmblob *blob)
 {
        int i;
        int error;
-       struct lsmblob blob;
        struct lsmcontext context;
 
-       security_current_getsecid_subj(&blob);
-       if (!lsmblob_is_set(&blob))
+       if (!lsmblob_is_set(blob))
                return 0;
 
        if (!lsm_multiple_contexts()) {
-               error = security_secid_to_secctx(&blob, &context,
-                                                LSMBLOB_FIRST);
+               error = security_secid_to_secctx(blob, &context, LSMBLOB_FIRST);
                if (error) {
                        if (error != -EINVAL)
                                goto error_path;
@@ -2254,15 +2251,15 @@ int audit_log_task_context(struct audit_buffer *ab)
                if (error)
                        goto error_path;
                for (i = 0; i < LSMBLOB_ENTRIES; i++) {
-                       if (blob.secid[i] == 0)
+                       if (blob->secid[i] == 0)
                                continue;
-                       error = security_secid_to_secctx(&blob, &context, i);
+                       error = security_secid_to_secctx(blob, &context, i);
                        if (error) {
                                audit_log_format(ab, "%ssubj_%s=?",
                                                 i ? " " : "",
                                                 lsm_slot_to_name(i));
                                if (error != -EINVAL)
-                                       audit_panic("error in 
audit_log_task_context");
+                                       audit_panic("error in 
audit_log_subject_context");
                        } else {
                                audit_log_format(ab, "%ssubj_%s=%s",
                                                 i ? " " : "",
@@ -2277,9 +2274,18 @@ int audit_log_task_context(struct audit_buffer *ab)
        return 0;
 
 error_path:
-       audit_panic("error in audit_log_task_context");
+       audit_panic("error in audit_log_subject_context");
        return error;
 }
+EXPORT_SYMBOL(audit_log_subject_context);
+
+int audit_log_task_context(struct audit_buffer *ab)
+{
+       struct lsmblob blob;
+
+       security_current_getsecid_subj(&blob);
+       return audit_log_subject_context(ab, &blob);
+}
 EXPORT_SYMBOL(audit_log_task_context);
 
 void audit_log_d_path_exe(struct audit_buffer *ab,
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index 1941877fd16f..42812bdfc31a 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -84,7 +84,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
                                               struct netlbl_audit *audit_info)
 {
        struct audit_buffer *audit_buf;
-       struct lsmcontext context;
        struct lsmblob blob;
 
        if (audit_enabled == AUDIT_OFF)
@@ -99,11 +98,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
                         audit_info->sessionid);
 
        lsmblob_init(&blob, audit_info->secid);
-       if (audit_info->secid != 0 &&
-           security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST) == 0) {
-               audit_log_format(audit_buf, " subj=%s", context.context);
-               security_release_secctx(&context);
-       }
+       audit_log_subject_context(audit_buf, &blob);
 
        return audit_buf;
 }
-- 
2.37.3

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