From mboxrd@z Thu Jan 1 00:00:00 1970 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 5D723C61DA4 for ; Thu, 23 Feb 2023 20:54:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229452AbjBWUym (ORCPT ); Thu, 23 Feb 2023 15:54:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229491AbjBWUyl (ORCPT ); Thu, 23 Feb 2023 15:54:41 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5367115CB7 for ; Thu, 23 Feb 2023 12:54:40 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1423E6178A for ; Thu, 23 Feb 2023 20:54:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B4FFC433EF; Thu, 23 Feb 2023 20:54:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1677185679; bh=G0c3gx/Khin0zmZaDBnyt1I+gWFEkiAXVfevSPnqkHo=; h=Date:To:From:Subject:From; b=u03u3BDJ1q/oWie5qcKRW6pu83pror8imvaQ4B99Z77psnC6dMSyctw0ABwjUeNgZ Q3AAXyqXap7nPVe7LrL7FgW6TcKeXT5PNvWZTsR79GngJWK0eGBRQQ841rkzr7rw7m qu+iMQkjFY2xc5vtXKTafIb8m9aDN+BsTAQ6nfAU= Date: Thu, 23 Feb 2023 12:54:38 -0800 To: mm-commits@vger.kernel.org, iii@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, zaslonko@linux.ibm.com, akpm@linux-foundation.org From: Andrew Morton Subject: + lib-zlib-dfltcc-deflate-does-not-write-all-available-bits-for-z_no_flush.patch added to mm-nonmm-unstable branch Message-Id: <20230223205439.3B4FFC433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: lib/zlib: DFLTCC deflate does not write all available bits for Z_NO_FLUSH has been added to the -mm mm-nonmm-unstable branch. Its filename is lib-zlib-dfltcc-deflate-does-not-write-all-available-bits-for-z_no_flush.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-zlib-dfltcc-deflate-does-not-write-all-available-bits-for-z_no_flush.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Mikhail Zaslonko Subject: lib/zlib: DFLTCC deflate does not write all available bits for Z_NO_FLUSH Date: Tue, 21 Feb 2023 14:16:17 +0100 DFLTCC deflate with Z_NO_FLUSH might generate a corrupted stream when the output buffer is not large enough to fit all the deflate output at once. The problem takes place on closing the deflate block since flush_pending() might leave some output bits not written. Similar problem for software deflate with Z_BLOCK flush option (not supported by kernel zlib deflate) has been fixed a while ago in userspace zlib but the fix never got to the kernel. Now flush_pending() flushes the bit buffer before copying out the byte buffer, in order to really flush as much as possible. Currently there are no users of DFLTCC deflate with Z_NO_FLUSH option in the kernel so the problem remained hidden for a while. This commit is based on the old zlib commit: https://github.com/madler/zlib/commit/0b828b4 Link: https://lkml.kernel.org/r/20230221131617.3369978-2-zaslonko@linux.ibm.com Signed-off-by: Mikhail Zaslonko Acked-by: Ilya Leoshkevich Cc: Heiko Carstens Cc: Vasily Gorbik Signed-off-by: Andrew Morton --- lib/zlib_deflate/defutil.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/lib/zlib_deflate/defutil.h~lib-zlib-dfltcc-deflate-does-not-write-all-available-bits-for-z_no_flush +++ a/lib/zlib_deflate/defutil.h @@ -420,9 +420,11 @@ static inline void flush_pending( z_streamp strm ) { + unsigned len; deflate_state *s = (deflate_state *) strm->state; - unsigned len = s->pending; + bi_flush(s); + len = s->pending; if (len > strm->avail_out) len = strm->avail_out; if (len == 0) return; _ Patches currently in -mm which might be from zaslonko@linux.ibm.com are lib-zlib-dfltcc-deflate-does-not-write-all-available-bits-for-z_no_flush.patch