From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Hocko , Christoph Hellwig , Tetsuo Handa , Al Viro , Andrew Morton , Linus Torvalds Subject: [PATCH 4.9 29/66] mm, fs: check for fatal signals in do_generic_file_read() Date: Tue, 7 Feb 2017 13:59:03 +0100 Message-Id: <20170207124529.565587493@linuxfoundation.org> In-Reply-To: <20170207124528.281881183@linuxfoundation.org> References: <20170207124528.281881183@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michal Hocko commit 5abf186a30a89d5b9c18a6bf93a2c192c9fd52f6 upstream. 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. Link: http://lkml.kernel.org/r/20170201092706.9966-3-mhocko@kernel.org Signed-off-by: Michal Hocko Reviewed-by: Christoph Hellwig Cc: Tetsuo Handa Cc: Al Viro Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/filemap.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1703,6 +1703,11 @@ static ssize_t do_generic_file_read(stru 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,