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 37382C6FA82 for ; Wed, 21 Sep 2022 20:01:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230153AbiIUUBW (ORCPT ); Wed, 21 Sep 2022 16:01:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229815AbiIUUBU (ORCPT ); Wed, 21 Sep 2022 16:01:20 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BAA8E86724 for ; Wed, 21 Sep 2022 13:01:19 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 51C5CB828F1 for ; Wed, 21 Sep 2022 20:01:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F8ABC433C1; Wed, 21 Sep 2022 20:01:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1663790476; bh=PZJcrKqmFUJVWDZjf8d/Dxa7jMsI10clU5NKRtg3J9Y=; h=Date:To:From:Subject:From; b=zxADMaKKdYuErRPe9JrbVNKJGR4P9ooy6DxcIh0Q6D1xHoJ+mYwlPcyNa6zr/gp1h cwmP1TKXsep6gAO8UNEFuRvX22rEBlcCri+5pI+enALuTWcIoZUxQra+kU7esHcMRL xGh8ELZlytERp4Bjv1r8ZUCLPpa9yIUJS02JFFjs= Date: Wed, 21 Sep 2022 13:01:14 -0700 To: mm-commits@vger.kernel.org, syzbot+1631f09646bc214d2e76@syzkaller.appspotmail.com, penguin-kernel@I-love.SAKURA.ne.jp, akpm@linux-foundation.org From: Andrew Morton Subject: + fs-ntfs3-fix-negative-shift-size-in-true_sectors_per_clst.patch added to mm-nonmm-unstable branch Message-Id: <20220921200116.8F8ABC433C1@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: fs/ntfs3: fix negative shift size in true_sectors_per_clst() has been added to the -mm mm-nonmm-unstable branch. Its filename is fs-ntfs3-fix-negative-shift-size-in-true_sectors_per_clst.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fs-ntfs3-fix-negative-shift-size-in-true_sectors_per_clst.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: Tetsuo Handa Subject: fs/ntfs3: fix negative shift size in true_sectors_per_clst() Date: Wed, 21 Sep 2022 00:59:27 +0900 syzbot is reporting shift-out-of-bounds in true_sectors_per_clst() [1], for commit a3b774342fa752a5 ("fs/ntfs3: validate BOOT sectors_per_clusters") did not address that (0 - boot->sectors_per_clusters) < 0 because "u8" was chosen for type of boot->sectors_per_clusters because 0x80 needs to be positive in order to support 64K clusters. Use "s8" cast in order to make sure that (0 - (s8) boot->sectors_per_clusters) > 0. Link: https://syzkaller.appspot.com/bug?extid=1631f09646bc214d2e76 [1] Link: https://lkml.kernel.org/r/4b37f037-3b10-b4e4-0644-73441c8fa0af@I-love.SAKURA.ne.jp Fixes: a3b774342fa752a5 ("fs/ntfs3: validate BOOT sectors_per_clusters") Reported-by: syzbot Signed-off-by: Tetsuo Handa Tested-by: syzbot Signed-off-by: Andrew Morton --- --- a/fs/ntfs3/super.c~fs-ntfs3-fix-negative-shift-size-in-true_sectors_per_clst +++ a/fs/ntfs3/super.c @@ -672,7 +672,7 @@ static u32 true_sectors_per_clst(const s if (boot->sectors_per_clusters <= 0x80) return boot->sectors_per_clusters; if (boot->sectors_per_clusters >= 0xf4) /* limit shift to 2MB max */ - return 1U << (0 - boot->sectors_per_clusters); + return 1U << (0 - (s8) boot->sectors_per_clusters); return -EINVAL; } _ Patches currently in -mm which might be from penguin-kernel@I-love.SAKURA.ne.jp are fs-ntfs3-fix-negative-shift-size-in-true_sectors_per_clst.patch