From patchwork Tue Jul 16 08:28:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roman Smirnov X-Patchwork-Id: 812895 Received: from mx01.omp.ru (mx01.omp.ru [90.154.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5414155894; Tue, 16 Jul 2024 08:29:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.154.21.10 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721118552; cv=none; b=Qa8zscGwwa1JORZE1TlalXGN8xd20xU2MypPfrvyraEkcBnuwPcheCqxFTug852gLc5TiuX8hoh9zNdRQf3qONaRg26UllEIgFic3flWbWhXHVI3UiOIeX62URl1bXzLdEI6DqWZ/YHkvfvu8nXO6CPI2/6q2keI03EfwwgBOLA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721118552; c=relaxed/simple; bh=k5rauxJZxRMqIwamxiJQ/u3NdfbdkSgq9d419Vy+jBM=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=Hl4SowgcF28MBnFdj4i7gNFCWaXP2tFTGiAXG+bRsZfjSWEeYEePib+jtn2NkeBJVsHMhpv8RRY3v4OXdtkfYU/QqnKP814pJunjeVsywITDkRg+aEfCXu49sgJI/yO9xmEOtX4SsNlGzbB/TfEDehtv8KUOMdtF6fr6RzGGvRw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=omp.ru; spf=pass smtp.mailfrom=omp.ru; arc=none smtp.client-ip=90.154.21.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=omp.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=omp.ru Received: from inp1wst083.omp.ru (81.22.207.138) by msexch01.omp.ru (10.188.4.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.1258.12; Tue, 16 Jul 2024 11:28:54 +0300 From: Roman Smirnov To: Herbert Xu , "David S. Miller" CC: Roman Smirnov , Mimi Zohar , Sergey Shtylyov , , , Subject: [PATCH] crypto: mpi: add NULL checks to mpi_normalize(). Date: Tue, 16 Jul 2024 11:28:25 +0300 Message-ID: <20240716082825.65219-1-r.smirnov@omp.ru> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: msexch01.omp.ru (10.188.4.12) To msexch01.omp.ru (10.188.4.12) X-KSE-ServerInfo: msexch01.omp.ru, 9 X-KSE-AntiSpam-Interceptor-Info: scan successful X-KSE-AntiSpam-Version: 6.1.0, Database issued on: 07/16/2024 07:59:51 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 19 X-KSE-AntiSpam-Info: Lua profiles 186530 [Jul 16 2024] X-KSE-AntiSpam-Info: Version: 6.1.0.4 X-KSE-AntiSpam-Info: Envelope from: r.smirnov@omp.ru X-KSE-AntiSpam-Info: LuaCore: 24 0.3.24 186c4d603b899ccfd4883d230c53f273b80e467f X-KSE-AntiSpam-Info: {rep_avail} X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: {SMTP from is not routable} X-KSE-AntiSpam-Info: {Found in DNSBL: 81.22.207.138 in (user) b.barracudacentral.org} X-KSE-AntiSpam-Info: {Found in DNSBL: 81.22.207.138 in (user) dbl.spamhaus.org} X-KSE-AntiSpam-Info: d41d8cd98f00b204e9800998ecf8427e.com:7.1.1; omp.ru:7.1.1; inp1wst083.omp.ru:7.1.1; 81.22.207.138:7.1.2; 127.0.0.199:7.1.2 X-KSE-AntiSpam-Info: ApMailHostAddress: 81.22.207.138 X-KSE-AntiSpam-Info: {DNS response errors} X-KSE-AntiSpam-Info: Rate: 19 X-KSE-AntiSpam-Info: Status: not_detected X-KSE-AntiSpam-Info: Method: none X-KSE-AntiSpam-Info: Auth:dmarc=temperror header.from=omp.ru;spf=temperror smtp.mailfrom=omp.ru;dkim=none X-KSE-Antiphishing-Info: Clean X-KSE-Antiphishing-ScanningType: Heuristic X-KSE-Antiphishing-Method: None X-KSE-Antiphishing-Bases: 07/16/2024 08:05:00 X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 7/16/2024 7:02:00 AM X-KSE-Attachment-Filter-Triggered-Rules: Clean X-KSE-Attachment-Filter-Triggered-Filters: Clean X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit If a->d is NULL, the NULL pointer will be dereferenced. It is necessary to prevent this case. There is at least one call stack that can lead to it: mpi_ec_curve_point() ec_pow2() ec_mulm() ec_mod() mpi_mod() mpi_fdiv_r() mpi_tdiv_r() mpi_tdiv_qr() mpi_resize() kcalloc() mpi_resize can return -ENOMEM, but this case is not handled in any way. Next, dereferencing takes place: mpi_ec_curve_point() mpi_cmp() do_mpi_cmp() mpi_normalize() Found by Linux Verification Center (linuxtesting.org) with Svace. Signed-off-by: Roman Smirnov --- lib/crypto/mpi/mpi-bit.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lib/crypto/mpi/mpi-bit.c b/lib/crypto/mpi/mpi-bit.c index 070ba784c9f1..d7420bdb4ff2 100644 --- a/lib/crypto/mpi/mpi-bit.c +++ b/lib/crypto/mpi/mpi-bit.c @@ -29,6 +29,9 @@ */ void mpi_normalize(MPI a) { + if (!a || !a->d) + return; + for (; a->nlimbs && !a->d[a->nlimbs - 1]; a->nlimbs--) ; }