From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EE300606A31C for ; Fri, 30 Oct 2026 15:05:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=N0aJW63N Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xMoAm-0002rZ-F3; Fri, 30 Oct 2026 11:05:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xMo9d-00025H-E6 for qemu-devel@nongnu.org; Fri, 30 Oct 2026 11:04:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xMo9a-0007Fz-C4 for qemu-devel@nongnu.org; Fri, 30 Oct 2026 11:04:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1793372665; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3ahEu6P9+WQGtrcigda+rkZcqqXsaiIlqMiVEDQP1EQ=; b=N0aJW63N349F0zbOvAwrprjZg9FjWDYMFLdWNGSDcbIPKia7/+e7UNlsHqdtTfuuixRIPa IcuRTVlPXOY/e80G47hWGLzwzvslXtF/igWRa5puDx64ZA/4xMTPLTTcwUnNzMYop+ex5o 5zWO72FcpBcdaApBn4qgutoS2CcUxec= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-257-xllzEd10MwK10aACsMGABA-1; Fri, 30 Oct 2026 11:04:19 -0400 X-MC-Unique: xllzEd10MwK10aACsMGABA-1 X-Mimecast-MFC-AGG-ID: xllzEd10MwK10aACsMGABA_1793372659 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C069B18009C4 for ; Fri, 30 Oct 2026 15:04:18 +0000 (UTC) Received: from berrange.csb (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0D4841956088; Fri, 30 Oct 2026 15:04:17 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Subject: [PATCH 3/3] crypto: add preventative measures wrt uninitialized hash info Date: Fri, 30 Oct 2026 15:04:13 +0000 Message-ID: <20261030150413.2999685-4-berrange@redhat.com> In-Reply-To: <20261030150413.2999685-1-berrange@redhat.com> References: <20261030150413.2999685-1-berrange@redhat.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-20.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Several static arrays can create incorrect behaviour if a new hash algorithm is added without them being explicitly initialized. Be more robust against this problem by using a static assert for the array size, instead of predeclaring the array size. When querying the arrays also add further sanity checks for missing initializers. Fixes: https://gitlab.com/qemu-project/qemu/-/work_items/4786 Signed-off-by: Daniel P. Berrangé --- crypto/hash-glib.c | 18 ++++++++++++++++-- crypto/hash.c | 12 +++++++++++- crypto/hmac-glib.c | 18 ++++++++++++++++-- 3 files changed, 43 insertions(+), 5 deletions(-) diff --git a/crypto/hash-glib.c b/crypto/hash-glib.c index 39040f1856e..d83caec8cab 100644 --- a/crypto/hash-glib.c +++ b/crypto/hash-glib.c @@ -25,7 +25,7 @@ #include "hashpriv.h" -static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALGO__MAX] = { +static int qcrypto_hash_alg_map[] = { [QCRYPTO_HASH_ALGO_MD5] = G_CHECKSUM_MD5, [QCRYPTO_HASH_ALGO_SHA1] = G_CHECKSUM_SHA1, [QCRYPTO_HASH_ALGO_SHA224] = -1, @@ -35,11 +35,25 @@ static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALGO__MAX] = { [QCRYPTO_HASH_ALGO_RIPEMD160] = -1, [QCRYPTO_HASH_ALGO_SM3] = -1, }; +/* + * Prefer the assert over declaring the array with + * size QCRYPTO_HASH_ALGO__MAX so we get better + * detection of uninitialize elements. + */ +G_STATIC_ASSERT(G_N_ELEMENTS(qcrypto_hash_alg_map) == + QCRYPTO_HASH_ALGO__MAX); gboolean qcrypto_hash_supports(QCryptoHashAlgo alg) { + /* + * The default static initializer value of 0 + * matches G_CHECKSUM_MD5, so protect against + * accidentally uninitialized fields + */ if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map) && - qcrypto_hash_alg_map[alg] != -1) { + qcrypto_hash_alg_map[alg] != -1 && + (alg == QCRYPTO_HASH_ALGO_MD5 || + qcrypto_hash_alg_map[alg] != G_CHECKSUM_MD5)) { return true; } return false; diff --git a/crypto/hash.c b/crypto/hash.c index 42a0a8ec56f..e966fc1a633 100644 --- a/crypto/hash.c +++ b/crypto/hash.c @@ -25,7 +25,7 @@ #include "crypto/hash.h" #include "hashpriv.h" -static size_t qcrypto_hash_alg_size[QCRYPTO_HASH_ALGO__MAX] = { +static size_t qcrypto_hash_alg_size[] = { [QCRYPTO_HASH_ALGO_MD5] = QCRYPTO_HASH_DIGEST_LEN_MD5, [QCRYPTO_HASH_ALGO_SHA1] = QCRYPTO_HASH_DIGEST_LEN_SHA1, [QCRYPTO_HASH_ALGO_SHA224] = QCRYPTO_HASH_DIGEST_LEN_SHA224, @@ -35,10 +35,20 @@ static size_t qcrypto_hash_alg_size[QCRYPTO_HASH_ALGO__MAX] = { [QCRYPTO_HASH_ALGO_RIPEMD160] = QCRYPTO_HASH_DIGEST_LEN_RIPEMD160, [QCRYPTO_HASH_ALGO_SM3] = QCRYPTO_HASH_DIGEST_LEN_SM3, }; +/* + * Prefer the assert over declaring the array with + * size QCRYPTO_HASH_ALGO__MAX so we get better + * detection of uninitialized elements. We don't + * want to ever return digest lengths of zero, as + * that risks a div-by-zero in callers. + */ +G_STATIC_ASSERT(G_N_ELEMENTS(qcrypto_hash_alg_size) == + QCRYPTO_HASH_ALGO__MAX); size_t qcrypto_hash_digest_len(QCryptoHashAlgo alg) { assert(alg < G_N_ELEMENTS(qcrypto_hash_alg_size)); + assert(qcrypto_hash_alg_size[alg] != 0); return qcrypto_hash_alg_size[alg]; } diff --git a/crypto/hmac-glib.c b/crypto/hmac-glib.c index 8f652c5064e..34090444083 100644 --- a/crypto/hmac-glib.c +++ b/crypto/hmac-glib.c @@ -17,7 +17,7 @@ #include "crypto/hmac.h" #include "hmacpriv.h" -static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALGO__MAX] = { +static int qcrypto_hmac_alg_map[] = { [QCRYPTO_HASH_ALGO_MD5] = G_CHECKSUM_MD5, [QCRYPTO_HASH_ALGO_SHA1] = G_CHECKSUM_SHA1, [QCRYPTO_HASH_ALGO_SHA256] = G_CHECKSUM_SHA256, @@ -27,6 +27,13 @@ static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALGO__MAX] = { [QCRYPTO_HASH_ALGO_RIPEMD160] = -1, [QCRYPTO_HASH_ALGO_SM3] = -1, }; +/* + * Prefer the assert over declaring the array with + * size QCRYPTO_HASH_ALGO__MAX so we get better + * detection of uninitialize elements. + */ +G_STATIC_ASSERT(G_N_ELEMENTS(qcrypto_hmac_alg_map) == + QCRYPTO_HASH_ALGO__MAX); typedef struct QCryptoHmacGlib QCryptoHmacGlib; struct QCryptoHmacGlib { @@ -35,8 +42,15 @@ struct QCryptoHmacGlib { bool qcrypto_hmac_supports(QCryptoHashAlgo alg) { + /* + * The default static initializer value of 0 + * matches G_CHECKSUM_MD5, so protect against + * accidentally uninitialized fields + */ if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) && - qcrypto_hmac_alg_map[alg] != -1) { + qcrypto_hmac_alg_map[alg] != -1 && + (alg == QCRYPTO_HASH_ALGO_MD5 || + qcrypto_hmac_alg_map[alg] != G_CHECKSUM_MD5)) { return true; } -- 2.56.0