From patchwork Mon Jul 12 06:02:13 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: 474128 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=-19.4 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 A38F8C07E9B for ; Mon, 12 Jul 2021 06:55:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9089561132 for ; Mon, 12 Jul 2021 06:55:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239575AbhGLG6T (ORCPT ); Mon, 12 Jul 2021 02:58:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:57966 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238626AbhGLG5c (ORCPT ); Mon, 12 Jul 2021 02:57:32 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 72EA061222; Mon, 12 Jul 2021 06:54:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626072874; bh=s0hSDXPGZNPiMQhMeECJGareszJcyKYanf7R9VEQUoI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aY9KUEqYWju9oXoz1zs+cTJ6tNe+Wfn0cMs/pjfFTJVUKnhUXdLFDVPR9kuSwslIq MK8BpUZ1UitxVmpCrGFHpHk7t2/8J7eeag+nTuaA4dabvEU/nJ71L4HaT3klBt03ow /rGEcVnsNaN5Oi6VsAB4nUo0oB+JWyuhU3ihPHTk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, stable@kernel.org, syzbot+2dcfeaf8cb49b05e8f1a@syzkaller.appspotmail.com, Anirudh Rayabharam , Theodore Tso Subject: [PATCH 5.12 050/700] ext4: fix kernel infoleak via ext4_extent_header Date: Mon, 12 Jul 2021 08:02:13 +0200 Message-Id: <20210712060931.769705818@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060924.797321836@linuxfoundation.org> References: <20210712060924.797321836@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Anirudh Rayabharam commit ce3aba43599f0b50adbebff133df8d08a3d5fffe upstream. Initialize eh_generation of struct ext4_extent_header to prevent leaking info to userspace. Fixes KMSAN kernel-infoleak bug reported by syzbot at: http://syzkaller.appspot.com/bug?id=78e9ad0e6952a3ca16e8234724b2fa92d041b9b8 Cc: stable@kernel.org Reported-by: syzbot+2dcfeaf8cb49b05e8f1a@syzkaller.appspotmail.com Fixes: a86c61812637 ("[PATCH] ext3: add extent map support") Signed-off-by: Anirudh Rayabharam Link: https://lore.kernel.org/r/20210506185655.7118-1-mail@anirudhrb.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/extents.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -825,6 +825,7 @@ void ext4_ext_tree_init(handle_t *handle eh->eh_entries = 0; eh->eh_magic = EXT4_EXT_MAGIC; eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); + eh->eh_generation = 0; ext4_mark_inode_dirty(handle, inode); } @@ -1090,6 +1091,7 @@ static int ext4_ext_split(handle_t *hand neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); neh->eh_magic = EXT4_EXT_MAGIC; neh->eh_depth = 0; + neh->eh_generation = 0; /* move remainder of path[depth] to the new leaf */ if (unlikely(path[depth].p_hdr->eh_entries != @@ -1167,6 +1169,7 @@ static int ext4_ext_split(handle_t *hand neh->eh_magic = EXT4_EXT_MAGIC; neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); neh->eh_depth = cpu_to_le16(depth - i); + neh->eh_generation = 0; fidx = EXT_FIRST_INDEX(neh); fidx->ei_block = border; ext4_idx_store_pblock(fidx, oldblock);