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 452B3C43217 for ; Thu, 13 Oct 2022 18:01:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230344AbiJMSBj (ORCPT ); Thu, 13 Oct 2022 14:01:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230349AbiJMSBf (ORCPT ); Thu, 13 Oct 2022 14:01:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF7F6252B2; Thu, 13 Oct 2022 11:01:21 -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 dfw.source.kernel.org (Postfix) with ESMTPS id BA0CD61912; Thu, 13 Oct 2022 17:57:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5C7CC433C1; Thu, 13 Oct 2022 17:57:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1665683844; bh=WxTjm5MReSjYjJAxBKI25pFq0/+t7woJOCT/OnWP32o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MUaGzmNVfpvWgEh1fEzyyu7MiZLWmpuFdLz6uh6xuYMPIXBjyKtgxwqej0dsP47cT wvKBdRmir/8fkA2YQ74B3FHaCWbTrXs0QPIHAxI+gxH6HS5CZxrsHUHJvA0AMnwvQT oV2vdj6KaksCDxRtLDZMgJK51yq5CUePAuFV81Dk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ryusuke Konishi , syzbot+b8c672b0e22615c80fe0@syzkaller.appspotmail.com, Khalid Masum , Andrew Morton Subject: [PATCH 5.15 02/27] nilfs2: fix use-after-free bug of struct nilfs_root Date: Thu, 13 Oct 2022 19:52:31 +0200 Message-Id: <20221013175143.616232783@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221013175143.518476113@linuxfoundation.org> References: <20221013175143.518476113@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ryusuke Konishi commit d325dc6eb763c10f591c239550b8c7e5466a5d09 upstream. If the beginning of the inode bitmap area is corrupted on disk, an inode with the same inode number as the root inode can be allocated and fail soon after. In this case, the subsequent call to nilfs_clear_inode() on that bogus root inode will wrongly decrement the reference counter of struct nilfs_root, and this will erroneously free struct nilfs_root, causing kernel oopses. This fixes the problem by changing nilfs_new_inode() to skip reserved inode numbers while repairing the inode bitmap. Link: https://lkml.kernel.org/r/20221003150519.39789-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Reported-by: syzbot+b8c672b0e22615c80fe0@syzkaller.appspotmail.com Reported-by: Khalid Masum Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/inode.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -332,6 +332,7 @@ struct inode *nilfs_new_inode(struct ino struct inode *inode; struct nilfs_inode_info *ii; struct nilfs_root *root; + struct buffer_head *bh; int err = -ENOMEM; ino_t ino; @@ -347,11 +348,25 @@ struct inode *nilfs_new_inode(struct ino ii->i_state = BIT(NILFS_I_NEW); ii->i_root = root; - err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh); + err = nilfs_ifile_create_inode(root->ifile, &ino, &bh); if (unlikely(err)) goto failed_ifile_create_inode; /* reference count of i_bh inherits from nilfs_mdt_read_block() */ + if (unlikely(ino < NILFS_USER_INO)) { + nilfs_warn(sb, + "inode bitmap is inconsistent for reserved inodes"); + do { + brelse(bh); + err = nilfs_ifile_create_inode(root->ifile, &ino, &bh); + if (unlikely(err)) + goto failed_ifile_create_inode; + } while (ino < NILFS_USER_INO); + + nilfs_info(sb, "repaired inode bitmap for reserved inodes"); + } + ii->i_bh = bh; + atomic64_inc(&root->inodes_count); inode_init_owner(&init_user_ns, inode, dir, mode); inode->i_ino = ino;