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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 22CC4C433DF for ; Fri, 19 Jun 2020 16:20:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF61C2168B for ; Fri, 19 Jun 2020 16:20:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592583631; bh=YizDRSUzjNO8ndVbmOGqc3pfS12tFWy066Lzh/CPDlk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LZBLFO9r1RcELxTqPkoq3d9mX5rnJGG1YWGu6m0XjR3eDj5yffPdvcfIlsoeT33qS TcY9izvpHIvcWNjN2sApxx9niIVw+g6gWiSHWUTpw7MmhtsW84gcGkq9t68o22fA0T ApSHzj5pp4iirD4IOuaXaeiJmxiOkGzzR7ZGboo8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394637AbgFSQU3 (ORCPT ); Fri, 19 Jun 2020 12:20:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:57944 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390717AbgFSPBd (ORCPT ); Fri, 19 Jun 2020 11:01:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 41E2321582; Fri, 19 Jun 2020 15:01:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592578892; bh=YizDRSUzjNO8ndVbmOGqc3pfS12tFWy066Lzh/CPDlk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pF6sPMxrWNEL1vvuw58mBATPq2ze7SxuUVqquIBlxVQ2j1XBaZP0RpOKGDGq0HqbT WaKvI7NUFyLcwJCNYmJKLcoshSO9W3hWkiUbYe1IxOYSDYi7TbRuA9KkA1MwDBJshh 1F59FjrYOaawANtYzZ+UunJS9P5nauAdKQE0gc1I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeffle Xu , Joseph Qi , Ritesh Harjani , Jan Kara , Theodore Tso , stable@kernel.org Subject: [PATCH 4.19 197/267] ext4: fix error pointer dereference Date: Fri, 19 Jun 2020 16:33:02 +0200 Message-Id: <20200619141658.201246929@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141648.840376470@linuxfoundation.org> References: <20200619141648.840376470@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jeffle Xu commit 8418897f1bf87da0cb6936489d57a4320c32c0af upstream. Don't pass error pointers to brelse(). commit 7159a986b420 ("ext4: fix some error pointer dereferences") has fixed some cases, fix the remaining one case. Once ext4_xattr_block_find()->ext4_sb_bread() failed, error pointer is stored in @bs->bh, which will be passed to brelse() in the cleanup routine of ext4_xattr_set_handle(). This will then cause a NULL panic crash in __brelse(). BUG: unable to handle kernel NULL pointer dereference at 000000000000005b RIP: 0010:__brelse+0x1b/0x50 Call Trace: ext4_xattr_set_handle+0x163/0x5d0 ext4_xattr_set+0x95/0x110 __vfs_setxattr+0x6b/0x80 __vfs_setxattr_noperm+0x68/0x1b0 vfs_setxattr+0xa0/0xb0 setxattr+0x12c/0x1a0 path_setxattr+0x8d/0xc0 __x64_sys_setxattr+0x27/0x30 do_syscall_64+0x60/0x250 entry_SYSCALL_64_after_hwframe+0x49/0xbe In this case, @bs->bh stores '-EIO' actually. Fixes: fb265c9cb49e ("ext4: add ext4_sb_bread() to disambiguate ENOMEM cases") Signed-off-by: Jeffle Xu Reviewed-by: Joseph Qi Cc: stable@kernel.org # 2.6.19 Reviewed-by: Ritesh Harjani Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/1587628004-95123-1-git-send-email-jefflexu@linux.alibaba.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/xattr.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -1824,8 +1824,11 @@ ext4_xattr_block_find(struct inode *inod if (EXT4_I(inode)->i_file_acl) { /* The inode already has an extended attribute block. */ bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO); - if (IS_ERR(bs->bh)) - return PTR_ERR(bs->bh); + if (IS_ERR(bs->bh)) { + error = PTR_ERR(bs->bh); + bs->bh = NULL; + return error; + } ea_bdebug(bs->bh, "b_count=%d, refcount=%d", atomic_read(&(bs->bh->b_count)), le32_to_cpu(BHDR(bs->bh)->h_refcount));