From patchwork Thu May  7 00:17:14 2020
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X-Patchwork-Submitter: Patrick Wildt <patrick@blueri.se>
X-Patchwork-Id: 245258
List-Id: U-Boot discussion <u-boot.lists.denx.de>
From: patrick at blueri.se (Patrick Wildt)
Date: Thu, 7 May 2020 02:17:14 +0200
Subject: efi_loader: pkcs7_parse_message() returns error pointer
Message-ID: <20200507001714.GA6487@nox.fritz.box>

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 at blueri.se>
Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>

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;
 		}