[PATCH v2] crypto: asymmetric_keys: fix uninitialized pointers with free attribute

[Ally Heev]

Uninitialized pointers with `__free` attribute can cause undefined
behavior as the memory assigned randomly to the pointer is freed
automatically when the pointer goes out of scope.

crypto/asymmetric_keys doesn't have any bugs related to this as of now,
but, it is better to initialize and assign pointers with `__free`
attribute in one statement to ensure proper scope-based cleanup

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/aPiG_F5EBQUjZqsl@stanley.mountain/
Signed-off-by: Ally Heev <allyheev@xxxxxxxxx>
---
Changes in v2:
- moved declarations to the top and initialized them with NULL
- Link to v1: https://lore.kernel.org/r/20251105-aheev-uninitialized-free-attr-crypto-v1-1-83da1e10e8c4@xxxxxxxxx
---
 crypto/asymmetric_keys/x509_cert_parser.c | 2 +-
 crypto/asymmetric_keys/x509_public_key.c  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 8df3fa60a44f80fbd71af17faeca2e92b6cc03ce..b37cae914987b69c996d6559058c00f13c92b5b9 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -60,7 +60,7 @@ EXPORT_SYMBOL_GPL(x509_free_certificate);
  */
 struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
 {
-	struct x509_certificate *cert __free(x509_free_certificate);
+	struct x509_certificate *cert __free(x509_free_certificate) = NULL;
 	struct x509_parse_context *ctx __free(kfree) = NULL;
 	struct asymmetric_key_id *kid;
 	long ret;
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 8409d7d36cb4f3582e15f9ee4d25f302b3b29358..12e3341e806b8db93803325a96a3821fd5d0a9f0 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -148,7 +148,7 @@ int x509_check_for_self_signed(struct x509_certificate *cert)
  */
 static int x509_key_preparse(struct key_preparsed_payload *prep)
 {
-	struct x509_certificate *cert __free(x509_free_certificate);
+	struct x509_certificate *cert __free(x509_free_certificate) = NULL;
 	struct asymmetric_key_ids *kids __free(kfree) = NULL;
 	char *p, *desc __free(kfree) = NULL;
 	const char *q;

---
base-commit: c9cfc122f03711a5124b4aafab3211cf4d35a2ac
change-id: 20251105-aheev-uninitialized-free-attr-crypto-bc94ec1b2253

Best regards,
-- 
Ally Heev <allyheev@xxxxxxxxx>