From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752012AbdBAJ1V (ORCPT ); Wed, 1 Feb 2017 04:27:21 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:35187 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751773AbdBAJ1S (ORCPT ); Wed, 1 Feb 2017 04:27:18 -0500 From: Michal Hocko To: Andrew Morton Cc: Christoph Hellwig , Tetsuo Handa , Al Viro , , , LKML , Michal Hocko Subject: [PATCH 2/3] mm, fs: check for fatal signals in do_generic_file_read Date: Wed, 1 Feb 2017 10:27:05 +0100 Message-Id: <20170201092706.9966-3-mhocko@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170201092706.9966-1-mhocko@kernel.org> References: <20170201092706.9966-1-mhocko@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michal Hocko do_generic_file_read can be told to perform a large request from userspace. If the system is under OOM and the reading task is the OOM victim then it has an access to memory reserves and finishing the full request can lead to the full memory depletion which is dangerous. Make sure we rather go with a short read and allow the killed task to terminate. Cc: stable Signed-off-by: Michal Hocko --- mm/filemap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index 14bddd0d7fa4..2ba46f410c7c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1797,6 +1797,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos, cond_resched(); find_page: + if (fatal_signal_pending(current)) { + error = -EINTR; + goto out; + } + page = find_get_page(mapping, index); if (!page) { page_cache_sync_readahead(mapping, -- 2.11.0