1 files changed, 61 insertions, 30 deletions

diff --git a/security/apparmor/context.c b/security/apparmor/context.c
index 89c03053303e..432672b18945 100644
--- a/security/apparmor/context.c
+++ b/security/apparmor/context.c
@@ -48,8 +48,6 @@ void aa_free_cred_ctx(struct aa_cred_ctx *ctx)
 {
 	if (ctx) {
 		aa_put_label(ctx->label);
-		aa_put_label(ctx->previous);
-		aa_put_label(ctx->onexec);
 
 		kzfree(ctx);
 	}
@@ -64,8 +62,6 @@ void aa_dup_cred_ctx(struct aa_cred_ctx *new, const struct aa_cred_ctx *old)
 {
 	*new = *old;
 	aa_get_label(new->label);
-	aa_get_label(new->previous);
-	aa_get_label(new->onexec);
 }
 
 /**
@@ -86,6 +82,43 @@ struct aa_label *aa_get_task_label(struct task_struct *task)
 }
 
 /**
+ * aa_alloc_task_ctx - allocate a new task_ctx
+ * @flags: gfp flags for allocation
+ *
+ * Returns: allocated buffer or NULL on failure
+ */
+struct aa_task_ctx *aa_alloc_task_ctx(gfp_t flags)
+{
+	return kzalloc(sizeof(struct aa_task_ctx), flags);
+}
+
+/**
+ * aa_free_task_ctx - free a task_ctx
+ * @ctx: task_ctx to free (MAYBE NULL)
+ */
+void aa_free_task_ctx(struct aa_task_ctx *ctx)
+{
+	if (ctx) {
+		aa_put_label(ctx->previous);
+		aa_put_label(ctx->onexec);
+
+		kzfree(ctx);
+	}
+}
+
+/**
+ * aa_dup_task_ctx - duplicate a task context, incrementing reference counts
+ * @new: a blank task context      (NOT NULL)
+ * @old: the task context to copy  (NOT NULL)
+ */
+void aa_dup_task_ctx(struct aa_task_ctx *new, const struct aa_task_ctx *old)
+{
+	*new = *old;
+	aa_get_label(new->previous);
+	aa_get_label(new->onexec);
+}
+
+/**
  * aa_replace_current_label - replace the current tasks label
  * @label: new label  (NOT NULL)
  *
@@ -112,7 +145,7 @@ int aa_replace_current_label(struct aa_label *label)
 		/* if switching to unconfined or a different label namespace
 		 * clear out context state
 		 */
-		aa_clear_cred_ctx_trans(ctx);
+		aa_clear_task_ctx_trans(current_task_ctx());
 
 	/*
 	 * be careful switching ctx->profile, when racing replacement it
@@ -136,18 +169,13 @@ int aa_replace_current_label(struct aa_label *label)
  */
 int aa_set_current_onexec(struct aa_label *label, bool stack)
 {
-	struct aa_cred_ctx *ctx;
-	struct cred *new = prepare_creds();
-	if (!new)
-		return -ENOMEM;
+	struct aa_task_ctx *ctx = current_task_ctx();
 
-	ctx = cred_ctx(new);
 	aa_get_label(label);
-	aa_clear_cred_ctx_trans(ctx);
+	aa_put_label(ctx->onexec);
 	ctx->onexec = label;
 	ctx->token = stack;
 
-	commit_creds(new);
 	return 0;
 }
 
@@ -163,28 +191,31 @@ int aa_set_current_onexec(struct aa_label *label, bool stack)
  */
 int aa_set_current_hat(struct aa_label *label, u64 token)
 {
+	struct aa_task_ctx *tctx = current_task_ctx();
 	struct aa_cred_ctx *ctx;
 	struct cred *new = prepare_creds();
+
 	if (!new)
 		return -ENOMEM;
 	AA_BUG(!label);
 
 	ctx = cred_ctx(new);
-	if (!ctx->previous) {
+	if (!tctx->previous) {
 		/* transfer refcount */
-		ctx->previous = ctx->label;
-		ctx->token = token;
-	} else if (ctx->token == token) {
+		tctx->previous = ctx->label;
+		tctx->token = token;
+	} else if (tctx->token == token) {
 		aa_put_label(ctx->label);
 	} else {
 		/* previous_profile && ctx->token != token */
 		abort_creds(new);
 		return -EACCES;
 	}
+
 	ctx->label = aa_get_newest_label(label);
 	/* clear exec on switching context */
-	aa_put_label(ctx->onexec);
-	ctx->onexec = NULL;
+	aa_put_label(tctx->onexec);
+	tctx->onexec = NULL;
 
 	commit_creds(new);
 	return 0;
@@ -201,28 +232,28 @@ int aa_set_current_hat(struct aa_label *label, u64 token)
  */
 int aa_restore_previous_label(u64 token)
 {
+	struct aa_task_ctx *tctx = current_task_ctx();
 	struct aa_cred_ctx *ctx;
-	struct cred *new = prepare_creds();
-	if (!new)
-		return -ENOMEM;
+	struct cred *new;
 
-	ctx = cred_ctx(new);
-	if (ctx->token != token) {
-		abort_creds(new);
+	if (tctx->token != token)
 		return -EACCES;
-	}
 	/* ignore restores when there is no saved label */
-	if (!ctx->previous) {
-		abort_creds(new);
+	if (!tctx->previous)
 		return 0;
-	}
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	ctx = cred_ctx(new);
 
 	aa_put_label(ctx->label);
-	ctx->label = aa_get_newest_label(ctx->previous);
+	ctx->label = aa_get_newest_label(tctx->previous);
 	AA_BUG(!ctx->label);
 	/* clear exec && prev information when restoring to previous context */
-	aa_clear_cred_ctx_trans(ctx);
+	aa_clear_task_ctx_trans(tctx);
 
 	commit_creds(new);
+
 	return 0;
 }