[PATCH 4/4] selftests/livepatch: fix mem leaks in test-klp-shadow-vars

[Yannick Cote <ycote@redhat.com>]

In some cases, when an error occurs during testing and the main test
routine returns, a memory leak occurs via leaving previously registered
shadow variables allocated in the kernel as well as shadow_ptr list
elements. From now on, in case of error, remove all allocated shadow
variables and shadow_ptr struct elements.

Signed-off-by: Yannick Cote <ycote@redhat.com>
---
 lib/livepatch/test_klp_shadow_vars.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/lib/livepatch/test_klp_shadow_vars.c b/lib/livepatch/test_klp_shadow_vars.c
index 195309e1edf3..c6d631d826e0 100644
--- a/lib/livepatch/test_klp_shadow_vars.c
+++ b/lib/livepatch/test_klp_shadow_vars.c
@@ -170,6 +170,7 @@ static int test_klp_shadow_vars_init(void)
 	char *pndup[NUM_OBJS];
 	int nfields2[NUM_OBJS], *pnfields2[NUM_OBJS], **sv2[NUM_OBJS];
 	void **sv;
+	int ret = -EINVAL;
 	int i;
 
 	ptr_id(NULL);
@@ -192,12 +193,16 @@ static int test_klp_shadow_vars_init(void)
 		/* alloc a few svars with different <obj> and <id>. */
 		sv1[i] = shadow_alloc(&objs[i], SV_ID1, sizeof(pnfields1[i]),
 					GFP_KERNEL, shadow_ctor, &pnfields1[i]);
-		if (!sv1[i])
-			return -ENOMEM;
+		if (!sv1[i]) {
+			ret = -ENOMEM;
+			goto out;
+		}
 		sv2[i] = shadow_alloc(&objs[i], SV_ID2, sizeof(pnfields2[i]),
 					GFP_KERNEL, shadow_ctor, &pnfields2[i]);
-		if (!sv2[i])
-			return -ENOMEM;
+		if (!sv2[i]) {
+			ret = -ENOMEM;
+			goto out;
+		}
 	}
 
 	/* pass 2: verify we find allocated svars and where they point to */
@@ -205,7 +210,7 @@ static int test_klp_shadow_vars_init(void)
 		/* check the "char" svar for all objects */
 		sv = shadow_get(&objs[i], SV_ID1);
 		if (!sv)
-			return -EINVAL;
+			goto out;
 		if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i])
 			pr_info("  got expected PTR%d -> PTR%d result\n",
 				ptr_id(sv1[i]), ptr_id(*sv1[i]));
@@ -213,7 +218,7 @@ static int test_klp_shadow_vars_init(void)
 		/* check the "int" svar for all objects */
 		sv = shadow_get(&objs[i], SV_ID2);
 		if (!sv)
-			return -EINVAL;
+			goto out;
 		if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i])
 			pr_info("  got expected PTR%d -> PTR%d result\n",
 				ptr_id(sv2[i]), ptr_id(*sv2[i]));
@@ -224,7 +229,7 @@ static int test_klp_shadow_vars_init(void)
 		sv = shadow_get_or_alloc(&objs[i], SV_ID1, sizeof(pndup[i]),
 					GFP_KERNEL, shadow_ctor, &pndup[i]);
 		if (!sv)
-			return -EINVAL;
+			goto out;
 		if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i])
 			pr_info("  got expected PTR%d -> PTR%d result\n",
 					ptr_id(sv1[i]), ptr_id(*sv1[i]));
@@ -242,7 +247,7 @@ static int test_klp_shadow_vars_init(void)
 	for (i = 0; i < NUM_OBJS; i++) {
 		sv = shadow_get(&objs[i], SV_ID2);	/* 'int' pairs */
 		if (!sv)
-			return -EINVAL;
+			goto out;
 		if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i])
 			pr_info("  got expected PTR%d -> PTR%d result\n",
 					ptr_id(sv2[i]), ptr_id(*sv2[i]));
@@ -259,6 +264,12 @@ static int test_klp_shadow_vars_init(void)
 	free_ptr_list();
 
 	return 0;
+out:
+	shadow_free_all(SV_ID1, NULL);		/* 'char' pairs */
+	shadow_free_all(SV_ID2, NULL);		/* 'int' pairs */
+	free_ptr_list();
+
+	return ret;
 }
 
 static void test_klp_shadow_vars_exit(void)
-- 
2.25.4