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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C0C2AC433E0 for ; Wed, 12 Aug 2020 01:36:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7904020658 for ; Wed, 12 Aug 2020 01:36:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="imqPfPuU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7904020658 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 326548D0064; Tue, 11 Aug 2020 21:36:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2D6AD8D0001; Tue, 11 Aug 2020 21:36:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1C5818D0064; Tue, 11 Aug 2020 21:36:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0036.hostedemail.com [216.40.44.36]) by kanga.kvack.org (Postfix) with ESMTP id F3D178D0001 for ; Tue, 11 Aug 2020 21:36:03 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id B9FD5181AEF10 for ; Wed, 12 Aug 2020 01:36:03 +0000 (UTC) X-FDA: 77140200606.13.rice79_16170c126fe7 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin13.hostedemail.com (Postfix) with ESMTP id 93B8318140B67 for ; Wed, 12 Aug 2020 01:36:03 +0000 (UTC) X-HE-Tag: rice79_16170c126fe7 X-Filterd-Recvd-Size: 2400 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Wed, 12 Aug 2020 01:36:03 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5D04920678; Wed, 12 Aug 2020 01:36:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597196162; bh=74NmFiFkDjo3W3PNUmjT3GwlYVTUsyl31JK1/8vnyAE=; h=Date:From:To:Subject:In-Reply-To:From; b=imqPfPuUnXBZ5n89IIdu0h/RlhHjyiQXU/VBXF8YGeXWueDb2BaI9AXk6HGr6oy10 6DDZ26At3UQNG2aIUpp4+UkREEtXKsB4olqZKRePJu2BYAWLwoPZoJ6slCfiO7brkC 33FlqwSzFprL+YwzA9yGsEjDpf8i6MBmzPd0jFz4= Date: Tue, 11 Aug 2020 18:36:01 -0700 From: Andrew Morton To: akpm@linux-foundation.org, hirofumi@mail.parknet.co.jp, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 110/165] fat: fix fat_ra_init() for data clusters == 0 Message-ID: <20200812013601.LbIXUhywg%akpm@linux-foundation.org> In-Reply-To: <20200811182949.e12ae9a472e3b5e27e16ad6c@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: 93B8318140B67 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: OGAWA Hirofumi Subject: fat: fix fat_ra_init() for data clusters == 0 If data clusters == 0, fat_ra_init() calls the ->ent_blocknr() for the cluster beyond ->max_clusters. This checks the limit before initialization to suppress the warning. Link: http://lkml.kernel.org/r/87mu462sv4.fsf@mail.parknet.co.jp Signed-off-by: OGAWA Hirofumi Reported-by: syzbot+756199124937b31a9b7e@syzkaller.appspotmail.com Signed-off-by: Andrew Morton --- fs/fat/fatent.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/fat/fatent.c~fat-fix-fat_ra_init-for-data-clusters-==-0 +++ a/fs/fat/fatent.c @@ -657,6 +657,9 @@ static void fat_ra_init(struct super_blo unsigned long ra_pages = sb->s_bdi->ra_pages; unsigned int reada_blocks; + if (fatent->entry >= ent_limit) + return; + if (ra_pages > sb->s_bdi->io_pages) ra_pages = rounddown(ra_pages, sb->s_bdi->io_pages); reada_blocks = ra_pages << (PAGE_SHIFT - sb->s_blocksize_bits + 1); _