From patchwork Wed Aug 21 14:01:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gao Xiang X-Patchwork-Id: 11106915 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2AF901805 for ; Wed, 21 Aug 2019 14:03:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 136AC233A1 for ; Wed, 21 Aug 2019 14:03:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729179AbfHUODF (ORCPT ); Wed, 21 Aug 2019 10:03:05 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:50194 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726484AbfHUODF (ORCPT ); Wed, 21 Aug 2019 10:03:05 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 37A035C532598535888E; Wed, 21 Aug 2019 22:02:46 +0800 (CST) Received: from architecture4.huawei.com (10.140.130.215) by smtp.huawei.com (10.3.19.208) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 21 Aug 2019 22:02:30 +0800 From: Gao Xiang To: Greg Kroah-Hartman CC: Chao Yu , , Miao Xie , LKML , , , , Gao Xiang , Subject: [PATCH v2 5/6] staging: erofs: detect potential multiref due to corrupted images Date: Wed, 21 Aug 2019 22:01:52 +0800 Message-ID: <20190821140152.229648-1-gaoxiang25@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190821021942.GA14087@kroah.com> References: <20190821021942.GA14087@kroah.com> MIME-Version: 1.0 X-Originating-IP: [10.140.130.215] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org As reported by erofs-utils fuzzer, currently, multiref (ondisk deduplication) hasn't been supported for now, we should forbid it properly. Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support") Cc: # 4.19+ Signed-off-by: Gao Xiang Reviewed-by: Chao Yu --- changelog from v1: - change err = -EFSCORRUPTED as well as Chao suggested; [ the difference between adding err or not to [PATCH 5/6] is just whether we error out the whole compressed cluster or partial of them (since some pages could be decompressed successfully), it's an undefined behavior for these corrupted compressed images... ] Hi Chao, Could you kindly review it again? Thanks! Hi Greg, This is [PATCH 5/6] of the original patchset, and I fix as what Chao suggested... But I'm not sure whether it should be merged right now, it is up to you. :) Thanks, Gao Xiang drivers/staging/erofs/zdata.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/staging/erofs/zdata.c b/drivers/staging/erofs/zdata.c index 4d6faaab04f5..60d7c20db87d 100644 --- a/drivers/staging/erofs/zdata.c +++ b/drivers/staging/erofs/zdata.c @@ -798,6 +798,7 @@ static int z_erofs_decompress_pcluster(struct super_block *sb, for (i = 0; i < nr_pages; ++i) pages[i] = NULL; + err = 0; z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS, cl->pagevec, 0); @@ -819,8 +820,17 @@ static int z_erofs_decompress_pcluster(struct super_block *sb, pagenr = z_erofs_onlinepage_index(page); DBG_BUGON(pagenr >= nr_pages); - DBG_BUGON(pages[pagenr]); + /* + * currently EROFS doesn't support multiref(dedup), + * so here erroring out one multiref page. + */ + if (unlikely(pages[pagenr])) { + DBG_BUGON(1); + SetPageError(pages[pagenr]); + z_erofs_onlinepage_endio(pages[pagenr]); + err = -EFSCORRUPTED; + } pages[pagenr] = page; } z_erofs_pagevec_ctor_exit(&ctor, true); @@ -828,7 +838,6 @@ static int z_erofs_decompress_pcluster(struct super_block *sb, overlapped = false; compressed_pages = pcl->compressed_pages; - err = 0; for (i = 0; i < clusterpages; ++i) { unsigned int pagenr; @@ -852,7 +861,12 @@ static int z_erofs_decompress_pcluster(struct super_block *sb, pagenr = z_erofs_onlinepage_index(page); DBG_BUGON(pagenr >= nr_pages); - DBG_BUGON(pages[pagenr]); + if (unlikely(pages[pagenr])) { + DBG_BUGON(1); + SetPageError(pages[pagenr]); + z_erofs_onlinepage_endio(pages[pagenr]); + err = -EFSCORRUPTED; + } pages[pagenr] = page; overlapped = true;