libkmod-module: check for NULL before accessing pointers

This introduces a few missing NULL-checks in public functions, and
align their docstrings with real behavior by getting rid of copy-paste
mistakes.

Signed-off-by: Luca Bruno <luca.bruno@coreos.com>

1 files changed, 10 insertions, 13 deletions

diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 0a3ef11..ee420f4 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -2519,7 +2519,7 @@ KMOD_EXPORT const char *kmod_module_version_get_symbol(const struct kmod_list *e
 {
 	struct kmod_module_version *version;
 
-	if (entry == NULL)
+	if (entry == NULL || entry->data == NULL)
 		return NULL;
 
 	version = entry->data;
@@ -2532,14 +2532,13 @@ KMOD_EXPORT const char *kmod_module_version_get_symbol(const struct kmod_list *e
  *
  * Get the crc of a kmod module version.
  *
- * Returns: the crc of this kmod module version on success or NULL on
- * failure. The string is owned by the version, do not free it.
+ * Returns: the crc of this kmod module version if available, otherwise default to 0.
  */
 KMOD_EXPORT uint64_t kmod_module_version_get_crc(const struct kmod_list *entry)
 {
 	struct kmod_module_version *version;
 
-	if (entry == NULL)
+	if (entry == NULL || entry->data == NULL)
 		return 0;
 
 	version = entry->data;
@@ -2660,7 +2659,7 @@ KMOD_EXPORT const char *kmod_module_symbol_get_symbol(const struct kmod_list *en
 {
 	struct kmod_module_symbol *symbol;
 
-	if (entry == NULL)
+	if (entry == NULL || entry->data == NULL)
 		return NULL;
 
 	symbol = entry->data;
@@ -2673,14 +2672,13 @@ KMOD_EXPORT const char *kmod_module_symbol_get_symbol(const struct kmod_list *en
  *
  * Get the crc of a kmod module symbol.
  *
- * Returns: the crc of this kmod module symbol on success or NULL on
- * failure. The string is owned by the symbol, do not free it.
+ * Returns: the crc of this kmod module symbol if available, otherwise default to 0.
  */
 KMOD_EXPORT uint64_t kmod_module_symbol_get_crc(const struct kmod_list *entry)
 {
 	struct kmod_module_symbol *symbol;
 
-	if (entry == NULL)
+	if (entry == NULL || entry->data == NULL)
 		return 0;
 
 	symbol = entry->data;
@@ -2806,7 +2804,7 @@ KMOD_EXPORT const char *kmod_module_dependency_symbol_get_symbol(const struct km
 {
 	struct kmod_module_dependency_symbol *dependency_symbol;
 
-	if (entry == NULL)
+	if (entry == NULL || entry->data == NULL)
 		return NULL;
 
 	dependency_symbol = entry->data;
@@ -2819,14 +2817,13 @@ KMOD_EXPORT const char *kmod_module_dependency_symbol_get_symbol(const struct km
  *
  * Get the crc of a kmod module dependency_symbol.
  *
- * Returns: the crc of this kmod module dependency_symbol on success or NULL on
- * failure. The string is owned by the dependency_symbol, do not free it.
+ * Returns: the crc of this kmod module dependency_symbol if available, otherwise default to 0.
  */
 KMOD_EXPORT uint64_t kmod_module_dependency_symbol_get_crc(const struct kmod_list *entry)
 {
 	struct kmod_module_dependency_symbol *dependency_symbol;
 
-	if (entry == NULL)
+	if (entry == NULL || entry->data == NULL)
 		return 0;
 
 	dependency_symbol = entry->data;
@@ -2846,7 +2843,7 @@ KMOD_EXPORT int kmod_module_dependency_symbol_get_bind(const struct kmod_list *e
 {
 	struct kmod_module_dependency_symbol *dependency_symbol;
 
-	if (entry == NULL)
+	if (entry == NULL || entry->data == NULL)
 		return 0;
 
 	dependency_symbol = entry->data;