From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58316 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932276AbdKFJrq (ORCPT ); Mon, 6 Nov 2017 04:47:46 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Jordan Crouse , Rob Clark , Ben Hutchings Subject: [PATCH 4.4 13/40] drm/msm: fix an integer overflow test Date: Mon, 6 Nov 2017 10:44:48 +0100 Message-Id: <20171106094501.877308129@linuxfoundation.org> In-Reply-To: <20171106094501.346859822@linuxfoundation.org> References: <20171106094501.346859822@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit 65e93108891e571f177c202add9288eda9ac4100 upstream. We recently added an integer overflow check but it needs an additional tweak to work properly on 32 bit systems. The problem is that we're doing the right hand side of the assignment as type unsigned long so the max it will have an integer overflow instead of being larger than SIZE_MAX. That means the "sz > SIZE_MAX" condition is never true even on 32 bit systems. We need to first cast it to u64 and then do the math. Fixes: 4a630fadbb29 ("drm/msm: Fix potential buffer overflow issue") Signed-off-by: Dan Carpenter Acked-by: Jordan Crouse Signed-off-by: Rob Clark Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/msm/msm_gem_submit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -37,7 +37,7 @@ static struct msm_gem_submit *submit_cre struct msm_gpu *gpu, uint32_t int nr) { struct msm_gem_submit *submit; - uint64_t sz = sizeof(*submit) + (nr * sizeof(submit->bos[0])); + uint64_t sz = sizeof(*submit) + ((u64)nr * sizeof(submit->bos[0])); if (sz > SIZE_MAX) return NULL;