From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98AE2C19774 for ; Mon, 3 May 2021 16:56:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7032261073 for ; Mon, 3 May 2021 16:56:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231542AbhECQ47 (ORCPT ); Mon, 3 May 2021 12:56:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:43348 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234401AbhECQxD (ORCPT ); Mon, 3 May 2021 12:53:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7074B61958; Mon, 3 May 2021 16:42:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620060123; bh=zdyythD21HvJgoFCj/9ADYkiuDf0zulSgc++zqebsM8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=heYlbIjWjziNCi8v6z4XxiRaz1XJQnqQHniHAun5EMoIb89MD4XUf7pRsKaMJX+h9 T+n3f2D8DkTZZIBZM7VnNCmBsRU8fl8j6MkK48P+jPMLEsODr4XX26yEr4PdIL4IZx pc/jcon9V42i15LdkCzSlkofClgB0hUD9bxDTZu7PqX+/ta8sli/L+z7dTPpIvbFe+ 8U8TerF8N2vWsW103VU9baWjTOILAFXl5CYwCw1xj+YhX5yx0YV2sjl9Zs1j+80mRR BbTpGbVYg0RAAH3h7LVZdEyyD/MRJaT2mBLSIYGvoIHv5kKKgs0zE6z+kpAiMWGzlC Ku1UQC2KX9I5Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Harald Freudenberger , Sven Schnelle , Heiko Carstens , Sasha Levin , linux-crypto@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 35/35] s390/archrandom: add parameter check for s390_arch_random_generate Date: Mon, 3 May 2021 12:41:09 -0400 Message-Id: <20210503164109.2853838-35-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210503164109.2853838-1-sashal@kernel.org> References: <20210503164109.2853838-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Harald Freudenberger [ Upstream commit 28096067686c5a5cbd4c35b079749bd805df5010 ] A review of the code showed, that this function which is exposed within the whole kernel should do a parameter check for the amount of bytes requested. If this requested bytes is too high an unsigned int overflow could happen causing this function to try to memcpy a really big memory chunk. This is not a security issue as there are only two invocations of this function from arch/s390/include/asm/archrandom.h and both are not exposed to userland. Reported-by: Sven Schnelle Signed-off-by: Harald Freudenberger Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/crypto/arch_random.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/s390/crypto/arch_random.c b/arch/s390/crypto/arch_random.c index dd95cdbd22ce..4cbb4b6d85a8 100644 --- a/arch/s390/crypto/arch_random.c +++ b/arch/s390/crypto/arch_random.c @@ -53,6 +53,10 @@ static DECLARE_DELAYED_WORK(arch_rng_work, arch_rng_refill_buffer); bool s390_arch_random_generate(u8 *buf, unsigned int nbytes) { + /* max hunk is ARCH_RNG_BUF_SIZE */ + if (nbytes > ARCH_RNG_BUF_SIZE) + return false; + /* lock rng buffer */ if (!spin_trylock(&arch_rng_lock)) return false; -- 2.30.2