From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net ([212.227.17.20]:52186 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750881AbbHNTRr (ORCPT ); Fri, 14 Aug 2015 15:17:47 -0400 From: Sven Joachim To: Greg KH Cc: Dick Snippe , stable@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: CVE-2015-1805 and 3.14-longterm? References: <20150702081934.GA13480@npo.nl> <20150814165533.GB32313@kroah.com> Date: Fri, 14 Aug 2015 21:17:49 +0200 In-Reply-To: <20150814165533.GB32313@kroah.com> (Greg KH's message of "Fri, 14 Aug 2015 09:55:33 -0700") Message-ID: <87h9o1brxe.fsf@turtle.gmx.de> MIME-Version: 1.0 Content-Type: text/plain Sender: stable-owner@vger.kernel.org List-ID: On 2015-08-14 18:55 +0200, Greg KH wrote: > On Thu, Jul 02, 2015 at 10:19:34AM +0200, Dick Snippe wrote: >> Hello, >> >> I'm sorry to bother you with this, but lwn.net reported a rather serious >> security issue a couple of weeks ago: >> >> http://lwn.net/Articles/646590/ >> https://bugzilla.redhat.com/show_bug.cgi?id=1202855 >> CVE-2015-1805 >> "It was found that the Linux kernel's implementation of vectored pipe >> read and write functionality did not take into account the I/O vectors >> that were already processed when retrying after a failed atomic access >> operation, potentially resulting in memory corruption due to an I/O >> vector array overrun. A local, unprivileged user could use this flaw to >> crash the system or, potentially, escalate their privileges on the >> system." >> >> It appears that these upstream fixes haven't made it to 3.14.4[456]: >> >> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f0d1bec9d58d4c038d0ac958c9af82be6eb18045 >> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=637b58c2887e5e57850865839cc75f59184b23d1 >> >> I'm just a (very happy!) user of the -longterm kernels, so I don't >> know how this normally works. But it would appear that this bug still >> exists in the -longterm kernels. > > I think, and I might be wrong here, but because > 637b58c2887e5e57850865839cc75f59184b23d1 (switch pipe_read() to > copy_page_to_iter()) is not in the 3.14-stable tree (it showed up in > 3.15), that f0d1bec9d58d4c038d0ac958c9af82be6eb18045 (new helper: > copy_page_from_iter()) isn't needed (it showed up in 3.16). > > So is this a problem in the 3.14-stable tree? It seems to have been fixed by 6b17faf3d5fa6a727c40613bdf24d73b2a59df27 (pipe: iovec: Fix memory corruption when retrying atomic copy as non-atomic) in 3.14.46. That fix is also in 3.10.82. Cheers, Sven