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 BAD87C433E0 for ; Wed, 12 Aug 2020 01:35:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9878F207DA for ; Wed, 12 Aug 2020 01:35:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597196126; bh=OUfkmlnS9oZDsBG34zAmOqH1i91rmucGYG8ZFVQCZhk=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=LdC3t8d60ldNBkyISKRSyY8eIrtePjwu7fJpHrc2o9MR7nSZbh+axcfRmUv8d5NzQ SXhwah6WpPHtxZ5/HSQHIL+TVkgKlpZCFonrwvOaimK6lrfxuBNrLYaGGGPPV4q1Io SCD9Eo444iV9VMkfN4YcT+NYmeXj8B3XoV/b9AUs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726473AbgHLBf0 (ORCPT ); Tue, 11 Aug 2020 21:35:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:36362 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726430AbgHLBf0 (ORCPT ); Tue, 11 Aug 2020 21:35:26 -0400 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 4C1EB2054F; Wed, 12 Aug 2020 01:35:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597196125; bh=OUfkmlnS9oZDsBG34zAmOqH1i91rmucGYG8ZFVQCZhk=; h=Date:From:To:Subject:In-Reply-To:From; b=gn3eSNf+3iC7Qi4l74deScdTZucjEOXTEllC1Sw6N3pBIarpdpGTfr263Jd6AEifF ubhsx35QPjDpQCaI+fc4KF3Ltt2yHoq155wMsF17MJLWIl2H7zhK8GcxSXDSEZyXsR y1OiC2mq9khv1bp7ZL8rj1rLE5l/99MCCYFv7gMw= Date: Tue, 11 Aug 2020 18:35:24 -0700 From: Andrew Morton To: akpm@linux-foundation.org, anenbupt@gmail.com, ebiggers@google.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, stable@vger.kernel.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk Subject: [patch 098/165] fs/minix: check return value of sb_getblk() Message-ID: <20200812013524.C4dEigLKz%akpm@linux-foundation.org> In-Reply-To: <20200811182949.e12ae9a472e3b5e27e16ad6c@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Eric Biggers Subject: fs/minix: check return value of sb_getblk() Patch series "fs/minix: fix syzbot bugs and set s_maxbytes". This series fixes all syzbot bugs in the minix filesystem: KASAN: null-ptr-deref Write in get_block KASAN: use-after-free Write in get_block KASAN: use-after-free Read in get_block WARNING in inc_nlink KMSAN: uninit-value in get_block WARNING in drop_nlink It also fixes the minix filesystem to set s_maxbytes correctly, so that userspace sees the correct behavior when exceeding the max file size. This patch (of 6): sb_getblk() can fail, so check its return value. This fixes a NULL pointer dereference. Originally from Qiujun Huang. Link: http://lkml.kernel.org/r/20200628060846.682158-1-ebiggers@kernel.org Link: http://lkml.kernel.org/r/20200628060846.682158-2-ebiggers@kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Biggers Reported-by: syzbot+4a88b2b9dc280f47baf4@syzkaller.appspotmail.com Cc: Qiujun Huang Cc: Alexander Viro Cc: Signed-off-by: Andrew Morton --- fs/minix/itree_common.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/fs/minix/itree_common.c~fs-minix-check-return-value-of-sb_getblk +++ a/fs/minix/itree_common.c @@ -75,6 +75,7 @@ static int alloc_branch(struct inode *in int n = 0; int i; int parent = minix_new_block(inode); + int err = -ENOSPC; branch[0].key = cpu_to_block(parent); if (parent) for (n = 1; n < num; n++) { @@ -85,6 +86,11 @@ static int alloc_branch(struct inode *in break; branch[n].key = cpu_to_block(nr); bh = sb_getblk(inode->i_sb, parent); + if (!bh) { + minix_free_block(inode, nr); + err = -ENOMEM; + break; + } lock_buffer(bh); memset(bh->b_data, 0, bh->b_size); branch[n].bh = bh; @@ -103,7 +109,7 @@ static int alloc_branch(struct inode *in bforget(branch[i].bh); for (i = 0; i < n; i++) minix_free_block(inode, block_to_cpu(branch[i].key)); - return -ENOSPC; + return err; } static inline int splice_branch(struct inode *inode, _