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, Benjamin LaHaise , Mateusz Guzik , Petr Matousek , Kent Overstreet , Jeff Moyer Subject: [PATCH 3.14 089/110] aio: fix kernel memory disclosure in io_getevents() introduced in v3.10 Date: Sat, 28 Jun 2014 10:47:26 -0700 Message-Id: <20140628174550.787475154@linuxfoundation.org> In-Reply-To: <20140628174545.354748696@linuxfoundation.org> References: <20140628174545.354748696@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin LaHaise commit edfbbf388f293d70bf4b7c0bc38774d05e6f711a upstream. A kernel memory disclosure was introduced in aio_read_events_ring() in v3.10 by commit a31ad380bed817aa25f8830ad23e1a0480fef797. The changes made to aio_read_events_ring() failed to correctly limit the index into ctx->ring_pages[], allowing an attacked to cause the subsequent kmap() of an arbitrary page with a copy_to_user() to copy the contents into userspace. This vulnerability has been assigned CVE-2014-0206. Thanks to Mateusz and Petr for disclosing this issue. This patch applies to v3.12+. A separate backport is needed for 3.10/3.11. Signed-off-by: Benjamin LaHaise Cc: Mateusz Guzik Cc: Petr Matousek Cc: Kent Overstreet Cc: Jeff Moyer Signed-off-by: Greg Kroah-Hartman --- fs/aio.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/aio.c +++ b/fs/aio.c @@ -1049,6 +1049,9 @@ static long aio_read_events_ring(struct if (head == tail) goto out; + head %= ctx->nr_events; + tail %= ctx->nr_events; + while (ret < nr) { long avail; struct io_event *ev;