From patchwork Tue Aug 10 17:30:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 495105 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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 66C10C432BE for ; Tue, 10 Aug 2021 17:34:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EA7761078 for ; Tue, 10 Aug 2021 17:34:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231152AbhHJReg (ORCPT ); Tue, 10 Aug 2021 13:34:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:38896 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232376AbhHJReD (ORCPT ); Tue, 10 Aug 2021 13:34:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8E5F161051; Tue, 10 Aug 2021 17:33:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628616821; bh=tPzkEkvjSFr0zA/73+SPlLNE/7l1MF7egMhoqkolLD4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WjgOt0R6ugqB0FhKejTbGXgZQKceEW/CrpLgFy7fhUtVlKZ0eW1ss7tzyY/0SE4XZ MxMVggUc0i4SM8MzHoRddSOVRaRQRIhsmGT3Ir3kzy9tvI3Ru3Xj0O7eAzn+giSmoM Stdrxeb6BqOJ4gZYQEvijj/PBivqVRC5YMUuYwUI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yu Kuai , Jan Kara , Sasha Levin Subject: [PATCH 4.19 50/54] reiserfs: add check for root_inode in reiserfs_fill_super Date: Tue, 10 Aug 2021 19:30:44 +0200 Message-Id: <20210810172945.853706935@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210810172944.179901509@linuxfoundation.org> References: <20210810172944.179901509@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yu Kuai [ Upstream commit 2acf15b94d5b8ea8392c4b6753a6ffac3135cd78 ] Our syzcaller report a NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 116e95067 P4D 116e95067 PUD 1080b5067 PMD 0 Oops: 0010 [#1] SMP KASAN CPU: 7 PID: 592 Comm: a.out Not tainted 5.13.0-next-20210629-dirty #67 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-p4 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffff888114e779b8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff110229cef39 RCX: ffffffffaa67e1aa RDX: 0000000000000000 RSI: ffff88810a58ee00 RDI: ffff8881233180b0 RBP: ffffffffac38e9c0 R08: ffffffffaa67e17e R09: 0000000000000001 R10: ffffffffb91c5557 R11: fffffbfff7238aaa R12: ffff88810a58ee00 R13: ffff888114e77aa0 R14: 0000000000000000 R15: ffff8881233180b0 FS: 00007f946163c480(0000) GS:ffff88839f1c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001099c1000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lookup_slow+0x116/0x2d0 ? page_put_link+0x120/0x120 ? __d_lookup+0xfc/0x320 ? d_lookup+0x49/0x90 lookup_one_len+0x13c/0x170 ? __lookup_slow+0x2d0/0x2d0 ? reiserfs_schedule_old_flush+0x31/0x130 reiserfs_lookup_privroot+0x64/0x150 reiserfs_fill_super+0x158c/0x1b90 ? finish_unfinished+0xb10/0xb10 ? bprintf+0xe0/0xe0 ? __mutex_lock_slowpath+0x30/0x30 ? __kasan_check_write+0x20/0x30 ? up_write+0x51/0xb0 ? set_blocksize+0x9f/0x1f0 mount_bdev+0x27c/0x2d0 ? finish_unfinished+0xb10/0xb10 ? reiserfs_kill_sb+0x120/0x120 get_super_block+0x19/0x30 legacy_get_tree+0x76/0xf0 vfs_get_tree+0x49/0x160 ? capable+0x1d/0x30 path_mount+0xacc/0x1380 ? putname+0x97/0xd0 ? finish_automount+0x450/0x450 ? kmem_cache_free+0xf8/0x5a0 ? putname+0x97/0xd0 do_mount+0xe2/0x110 ? path_mount+0x1380/0x1380 ? copy_mount_options+0x69/0x140 __x64_sys_mount+0xf0/0x190 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae This is because 'root_inode' is initialized with wrong mode, and it's i_op is set to 'reiserfs_special_inode_operations'. Thus add check for 'root_inode' to fix the problem. Link: https://lore.kernel.org/r/20210702040743.1918552-1-yukuai3@huawei.com Signed-off-by: Yu Kuai Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/reiserfs/super.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index ec5716dd58c2..831a542c22c6 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -2085,6 +2085,14 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent) unlock_new_inode(root_inode); } + if (!S_ISDIR(root_inode->i_mode) || !inode_get_bytes(root_inode) || + !root_inode->i_size) { + SWARN(silent, s, "", "corrupt root inode, run fsck"); + iput(root_inode); + errval = -EUCLEAN; + goto error; + } + s->s_root = d_make_root(root_inode); if (!s->s_root) goto error;