From:   Vitaly Chikunov <vt@altlinux.org>
To:     Mimi Zohar <zohar@linux.vnet.ibm.com>,
        Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
        linux-integrity@vger.kernel.org
Subject: [PATCH] ima-evm-utils: fix memory leak in ima_calc_hash
Date:   Wed,  6 Feb 2019 15:47:27 +0300
Message-Id: <20190206124727.2207-1-vt@altlinux.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-integrity-owner@vger.kernel.org
Precedence: bulk

Free EVP_MD_CTX in ima_calc_hash(). Also, remove legacy EVP_MD_CTX usage.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
---
 src/libimaevm.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/libimaevm.c b/src/libimaevm.c
index 6070614..dccb74c 100644
--- a/src/libimaevm.c
+++ b/src/libimaevm.c
@@ -322,12 +322,6 @@ int ima_calc_hash(const char *file, uint8_t *hash)
 	EVP_MD_CTX *pctx;
 	unsigned int mdlen;
 	int err;
-#if OPENSSL_VERSION_NUMBER < 0x10100000
-	EVP_MD_CTX ctx;
-	pctx = &ctx;
-#else
-	pctx = EVP_MD_CTX_new();
-#endif
 
 	/*  Need to know the file length */
 	err = lstat(file, &st);
@@ -342,9 +336,11 @@ int ima_calc_hash(const char *file, uint8_t *hash)
 		return 1;
 	}
 
+	pctx = EVP_MD_CTX_new();
 	err = EVP_DigestInit(pctx, md);
 	if (!err) {
 		log_err("EVP_DigestInit() failed\n");
+		EVP_MD_CTX_free(pctx);
 		return 1;
 	}
 
@@ -364,18 +360,21 @@ int ima_calc_hash(const char *file, uint8_t *hash)
 		break;
 	default:
 		log_errno("Unsupported file type");
+		EVP_MD_CTX_free(pctx);
 		return -1;
 	}
 
-	if (err)
+	if (err) {
+		EVP_MD_CTX_free(pctx);
 		return err;
+	}
 
 	err = EVP_DigestFinal(pctx, hash, &mdlen);
+	EVP_MD_CTX_free(pctx);
 	if (!err) {
 		log_err("EVP_DigestFinal() failed\n");
 		return 1;
 	}
-
 	return mdlen;
 }
 
-- 
2.11.0