From: Ally Heev <allyheev@gmail.com>
To: David Howells <dhowells@redhat.com>,
Lukas Wunner <lukas@wunner.de>,
Ignat Korchagin <ignat@cloudflare.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>
Cc: keyrings@vger.kernel.org, linux-crypto@vger.kernel.org,
linux-kernel@vger.kernel.org,
Dan Carpenter <dan.carpenter@linaro.org>,
Ally Heev <allyheev@gmail.com>
Subject: [PATCH] crypto: asymmetric_keys: fix uninitialized pointers with free attr
Date: Wed, 05 Nov 2025 15:23:08 +0530 [thread overview]
Message-ID: <20251105-aheev-uninitialized-free-attr-crypto-v1-1-83da1e10e8c4@gmail.com> (raw)
Uninitialized pointers with `__free` attribute can cause undefined
behaviour 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` attr
in one statement to ensure proper scope-based cleanup
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/aPiG_F5EBQUjZqsl@stanley.mountain/
Signed-off-by: Ally Heev <allyheev@gmail.com>
---
crypto/asymmetric_keys/x509_cert_parser.c | 11 +++++++----
crypto/asymmetric_keys/x509_public_key.c | 14 ++++++++------
2 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 8df3fa60a44f80fbd71af17faeca2e92b6cc03ce..bfd2cb2a9d81e3c615dfd4fe6f41653869a8cbd6 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -60,12 +60,12 @@ 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_parse_context *ctx __free(kfree) = NULL;
struct asymmetric_key_id *kid;
long ret;
- cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
+ struct x509_certificate *cert __free(x509_free_certificate) = kzalloc(
+ sizeof(struct x509_certificate), GFP_KERNEL);
+
if (!cert)
return ERR_PTR(-ENOMEM);
cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
@@ -74,7 +74,10 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
if (!cert->sig)
return ERR_PTR(-ENOMEM);
- ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
+
+ struct x509_parse_context *ctx __free(kfree) = kzalloc(
+ sizeof(struct x509_parse_context), GFP_KERNEL);
+
if (!ctx)
return ERR_PTR(-ENOMEM);
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 8409d7d36cb4f3582e15f9ee4d25f302b3b29358..818c9ab5d63940ff62c21666fd549d3a1ff07e67 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -148,13 +148,13 @@ 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 asymmetric_key_ids *kids __free(kfree) = NULL;
- char *p, *desc __free(kfree) = NULL;
+ char *p;
const char *q;
size_t srlen, sulen;
- cert = x509_cert_parse(prep->data, prep->datalen);
+ struct x509_certificate *cert __free(x509_free_certificate) =
+ x509_cert_parse(prep->data, prep->datalen);
+
if (IS_ERR(cert))
return PTR_ERR(cert);
@@ -187,7 +187,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
q = cert->raw_serial;
}
- desc = kmalloc(sulen + 2 + srlen * 2 + 1, GFP_KERNEL);
+ char *desc __free(kfree) = kmalloc(sulen + 2 + srlen * 2 + 1, GFP_KERNEL);
if (!desc)
return -ENOMEM;
p = memcpy(desc, cert->subject, sulen);
@@ -197,7 +197,9 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
p = bin2hex(p, q, srlen);
*p = 0;
- kids = kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL);
+ struct asymmetric_key_ids *kids __free(kfree) = kmalloc(
+ sizeof(struct asymmetric_key_ids), GFP_KERNEL);
+
if (!kids)
return -ENOMEM;
kids->id[0] = cert->id;
---
base-commit: c9cfc122f03711a5124b4aafab3211cf4d35a2ac
change-id: 20251105-aheev-uninitialized-free-attr-crypto-bc94ec1b2253
Best regards,
--
Ally Heev <allyheev@gmail.com>
next reply other threads:[~2025-11-05 9:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-05 9:53 Ally Heev [this message]
2025-11-11 13:12 ` [PATCH] crypto: asymmetric_keys: fix uninitialized pointers with free attr Ignat Korchagin
2025-11-11 13:36 ` ally heev
2025-11-22 14:23 ` Krzysztof Kozlowski
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