On 07.05.20 02:17, Patrick Wildt wrote:

Since pkcs7_parse_message() returns an error pointer, we must not check for NULL. We have to explicitly set msg to NULL in the error case, otherwise the call to pkcs7_free_message() on the goto err path will assume it's a valid object.

@Takahiro I think we should start documenting the library functions properly. The description in lib/crypto/pkcs7_parser.c does not conform to https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-do... Especially we should describe how errors are returned.

Best regards

Heinrich

Signed-off-by: Patrick Wildt patrick@blueri.se

diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c index 5a9a6424cc..43a53d3dd1 100644 --- a/lib/efi_loader/efi_image_loader.c +++ b/lib/efi_loader/efi_image_loader.c @@ -538,8 +538,9 @@ static bool efi_image_authenticate(void *efi, size_t efi_size) } msg = pkcs7_parse_message((void *)wincert + sizeof(*wincert), wincert->dwLength - sizeof(*wincert));

• if (!msg) {
  

• if (IS_ERR(msg)) {
  debug("Parsing image's signature failed\n");
  

• 	msg = NULL;
  goto err;
  

  }

On 07.05.20 02:17, Patrick Wildt wrote:

Since pkcs7_parse_message() returns an error pointer, we must not check for NULL. We have to explicitly set msg to NULL in the error case, otherwise the call to pkcs7_free_message() on the goto err path will assume it's a valid object.

Signed-off-by: Patrick Wildt patrick@blueri.se

diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c index 5a9a6424cc..43a53d3dd1 100644 --- a/lib/efi_loader/efi_image_loader.c +++ b/lib/efi_loader/efi_image_loader.c @@ -538,8 +538,9 @@ static bool efi_image_authenticate(void *efi, size_t efi_size) } msg = pkcs7_parse_message((void *)wincert + sizeof(*wincert), wincert->dwLength - sizeof(*wincert));

• if (!msg) {
  

• if (IS_ERR(msg)) {
  

Compiling with sandbox_defconfig results in:

lib/efi_loader/efi_image_loader.c: In function ‘efi_image_authenticate’: lib/efi_loader/efi_image_loader.c:541:7: warning: implicit declaration of function ‘IS_ERR’ [-Wimplicit-function-declaration] 541 | if (IS_ERR(msg)) { | ^~~~~~

I will add the missing #include <linux/err.h> when merging.

Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de

	debug("Parsing image's signature failed\n");

• 	msg = NULL;
  goto err;
  

  }