Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E24EC433FE for ; Thu, 13 Jan 2022 12:33:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234541AbiAMMd2 (ORCPT ); Thu, 13 Jan 2022 07:33:28 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:38102 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S233633AbiAMMd0 (ORCPT ); Thu, 13 Jan 2022 07:33:26 -0500 X-UUID: a357bcd85de4422e9e90e55554a8dd4d-20220113 X-UUID: a357bcd85de4422e9e90e55554a8dd4d-20220113 Received: from mtkcas11.mediatek.inc [(172.21.101.40)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1167861225; Thu, 13 Jan 2022 20:33:19 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.3; Thu, 13 Jan 2022 20:33:17 +0800 Received: from mszswglt01.gcn.mediatek.inc (10.16.20.20) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 13 Jan 2022 20:33:16 +0800 From: To: CC: , , , , , , , , , , , , , , , , , , , , Guangming Subject: [PATCH v3] dma-buf: dma-heap: Add a size check for allocation Date: Thu, 13 Jan 2022 20:34:06 +0800 Message-ID: <20220113123406.11520-1-guangming.cao@mediatek.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guangming Add a size check for allocation since the allocation size is always less than the total DRAM size. Without this check, once the invalid size allocation runs on a process that can't be killed by OOM flow(such as "gralloc" on Android devices), it will cause a kernel exception, and to make matters worse, we can't find who are using so many memory with "dma_buf_debug_show" since the relevant dma-buf hasn't exported. To make OOM issue easier, maybe need dma-buf framework to dump the buffer size under allocating in "dma_buf_debug_show". Signed-off-by: Guangming Signed-off-by: jianjiao zeng --- v3: 1. update patch, use right shift to replace division. 2. update patch, add reason in code and commit message. v2: 1. update size limitation as total_dram page size. 2. update commit message --- drivers/dma-buf/dma-heap.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 56bf5ad01ad5..1fd382712584 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -55,6 +55,16 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, struct dma_buf *dmabuf; int fd; + /* + * Invalid size check. The "len" should be less than totalram. + * + * Without this check, once the invalid size allocation runs on a process that + * can't be killed by OOM flow(such as "gralloc" on Android devices), it will + * cause a kernel exception, and to make matters worse, we can't find who are using + * so many memory with "dma_buf_debug_show" since the relevant dma-buf hasn't exported. + */ + if (len >> PAGE_SHIFT > totalram_pages()) + return -EINVAL; /* * Allocations from all heaps have to begin * and end on page boundaries. -- 2.17.1