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,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 53047C2D0D1 for ; Sun, 29 Dec 2019 17:37:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23DB6206CB for ; Sun, 29 Dec 2019 17:37:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577641040; bh=qrhojyInostG08jDUHhc2sQ2864qtece+1w70v2oIRA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xPYhr8kV/zdc+WBNYXmSjEAGvmc26azPUN7qor9nEudI6GBaS5ueCsMi7GgFx8DDT 2cAwwk7MRp5YKZGCbPGUMToI9smhGowDzAk2ech4u8eBepkQ9GBt843ZS4+Tqrlf2O 2Rtiqbuaw6psz1xQcZ2nVhwnA4FKbS1MqTWK/PeI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729756AbfL2Rfy (ORCPT ); Sun, 29 Dec 2019 12:35:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:40684 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729752AbfL2Rfy (ORCPT ); Sun, 29 Dec 2019 12:35:54 -0500 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 3664D20722; Sun, 29 Dec 2019 17:35:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577640953; bh=qrhojyInostG08jDUHhc2sQ2864qtece+1w70v2oIRA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mv3SflnOlRgNhVBOmIuw4zzmLrXkP6HViLZd5PqNzlIXqq3k5SmJd+T+U2QWNwVKy moXa4pC9z/qQmllwOSMwVzt85+NZB6G8FDZ9VyhPdTrhfOPRyGExqsK7dNvQxpMnJC iX2M1c7EON65tGVaeGWG078bozUzl9D38RVhPt1U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , Theodore Tso Subject: [PATCH 4.19 206/219] ext4: check for directory entries too close to block end Date: Sun, 29 Dec 2019 18:20:08 +0100 Message-Id: <20191229162541.343792506@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191229162508.458551679@linuxfoundation.org> References: <20191229162508.458551679@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jan Kara commit 109ba779d6cca2d519c5dd624a3276d03e21948e upstream. ext4_check_dir_entry() currently does not catch a case when a directory entry ends so close to the block end that the header of the next directory entry would not fit in the remaining space. This can lead to directory iteration code trying to access address beyond end of current buffer head leading to oops. CC: stable@vger.kernel.org Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20191202170213.4761-3-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/dir.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -77,6 +77,11 @@ int __ext4_check_dir_entry(const char *f error_msg = "rec_len is too small for name_len"; else if (unlikely(((char *) de - buf) + rlen > size)) error_msg = "directory entry overrun"; + else if (unlikely(((char *) de - buf) + rlen > + size - EXT4_DIR_REC_LEN(1) && + ((char *) de - buf) + rlen != size)) { + error_msg = "directory entry too close to block end"; + } else if (unlikely(le32_to_cpu(de->inode) > le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) error_msg = "inode out of bounds";