From patchwork Sun Jun 28 06:08:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11629925 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 1AD66618 for ; Sun, 28 Jun 2020 06:11:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E960D20702 for ; Sun, 28 Jun 2020 06:11:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593324666; bh=4KTwlwAS3yf9rIisW3dStoZMc/64VWd7yIvASpVgF40=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2FF1iceHwv7qu6mv71Qye0jfoO67FwKaASyBzCEd/dIz0sO9XuS03fiXjiGpyWEkM dzGsKT7h25qmWzNaFwecKPdTIpeNzCvnFtFGKwJYYSEfmTrl3iqwPJ1XYLxSr/c4yw stE6wjfXUlQbnOTUIRa1pSaC+/+O0H4/QQBKKxs4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726060AbgF1GKg (ORCPT ); Sun, 28 Jun 2020 02:10:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:41978 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725913AbgF1GKf (ORCPT ); Sun, 28 Jun 2020 02:10:35 -0400 Received: from sol.hsd1.ca.comcast.net (c-107-3-166-239.hsd1.ca.comcast.net [107.3.166.239]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C8CF22071A; Sun, 28 Jun 2020 06:10:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593324635; bh=4KTwlwAS3yf9rIisW3dStoZMc/64VWd7yIvASpVgF40=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tys1hkuGTt37lRSXE/p9UQUesp1Q878EE0/Bh+8Rr1uBrMOLeeQuoHS07uJ9+Xejn wYzY1rOxJEaJkR0jPswIE1d2ygau1oCcvrZmR+CFkKwaAVtvmmpffNjjxCM98vYE4/ BmDoz86MXWDaSEKqc70KxAswCR9MLwvR4r7SRS2g= From: Eric Biggers To: linux-fsdevel@vger.kernel.org, Alexander Viro , Andrew Morton Cc: linux-kernel@vger.kernel.org, Qiujun Huang , stable@vger.kernel.org, syzbot+a9ac3de1b5de5fb10efc@syzkaller.appspotmail.com, syzbot+df958cf5688a96ad3287@syzkaller.appspotmail.com Subject: [PATCH 2/6] fs/minix: don't allow getting deleted inodes Date: Sat, 27 Jun 2020 23:08:41 -0700 Message-Id: <20200628060846.682158-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200628060846.682158-1-ebiggers@kernel.org> References: <20200628060846.682158-1-ebiggers@kernel.org> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Eric Biggers If an inode has no links, we need to mark it bad rather than allowing it to be accessed. This avoids WARNINGs in inc_nlink() and drop_nlink() when doing directory operations on a fuzzed filesystem. Reported-by: syzbot+a9ac3de1b5de5fb10efc@syzkaller.appspotmail.com Reported-by: syzbot+df958cf5688a96ad3287@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers --- fs/minix/inode.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/fs/minix/inode.c b/fs/minix/inode.c index 7cb5fd38eb14..2bca95abe8f4 100644 --- a/fs/minix/inode.c +++ b/fs/minix/inode.c @@ -468,6 +468,13 @@ static struct inode *V1_minix_iget(struct inode *inode) iget_failed(inode); return ERR_PTR(-EIO); } + if (raw_inode->i_nlinks == 0) { + printk("MINIX-fs: deleted inode referenced: %lu\n", + inode->i_ino); + brelse(bh); + iget_failed(inode); + return ERR_PTR(-ESTALE); + } inode->i_mode = raw_inode->i_mode; i_uid_write(inode, raw_inode->i_uid); i_gid_write(inode, raw_inode->i_gid); @@ -501,6 +508,13 @@ static struct inode *V2_minix_iget(struct inode *inode) iget_failed(inode); return ERR_PTR(-EIO); } + if (raw_inode->i_nlinks == 0) { + printk("MINIX-fs: deleted inode referenced: %lu\n", + inode->i_ino); + brelse(bh); + iget_failed(inode); + return ERR_PTR(-ESTALE); + } inode->i_mode = raw_inode->i_mode; i_uid_write(inode, raw_inode->i_uid); i_gid_write(inode, raw_inode->i_gid);