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 5CF3CC76196 for ; Tue, 11 Apr 2023 04:37:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229700AbjDKEhv (ORCPT ); Tue, 11 Apr 2023 00:37:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229507AbjDKEhu (ORCPT ); Tue, 11 Apr 2023 00:37:50 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2DFE10DC; Mon, 10 Apr 2023 21:37:49 -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 3D63161F27; Tue, 11 Apr 2023 04:37:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95C91C433EF; Tue, 11 Apr 2023 04:37:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1681187868; bh=Gae+XT0KkZG+Xqo7hiJSie1samATP5Tw4z6ya6g8EDU=; h=Date:To:From:Subject:From; b=xRleMGLLzLQfN8PsWUevgCP5anxnTbYz4eZvG6V8ZWB0998NhXALDU+ikvmmR66+8 HbVcXdvigMhEJdovFnNyZnlT4JJzqkEHTqiQVtMLC+1vVacCVeTfGIarg+FdY6Upp5 HkrpNg6UBSydGCrq+UuS0LDXWjVWyonEW4UmQ1L8= Date: Mon, 10 Apr 2023 21:37:47 -0700 To: mm-commits@vger.kernel.org, stable@vger.kernel.org, Liam.Howlett@Oracle.com, zhangpeng.00@bytedance.com, akpm@linux-foundation.org From: Andrew Morton Subject: + maple_tree-fix-a-potential-memory-leak-oob-access-or-other-unpredictable-bug.patch added to mm-hotfixes-unstable branch Message-Id: <20230411043748.95C91C433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: maple_tree: fix a potential memory leak, OOB access, or other unpredictable bug has been added to the -mm mm-hotfixes-unstable branch. Its filename is maple_tree-fix-a-potential-memory-leak-oob-access-or-other-unpredictable-bug.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-fix-a-potential-memory-leak-oob-access-or-other-unpredictable-bug.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Peng Zhang Subject: maple_tree: fix a potential memory leak, OOB access, or other unpredictable bug Date: Tue, 11 Apr 2023 12:10:04 +0800 In mas_alloc_nodes(), "node->node_count = 0" means to initialize the node_count field of the new node, but the node may not be a new node. It may be a node that existed before and node_count has a value, setting it to 0 will cause a memory leak. At this time, mas->alloc->total will be greater than the actual number of nodes in the linked list, which may cause many other errors. For example, out-of-bounds access in mas_pop_node(), and mas_pop_node() may return addresses that should not be used. Fix it by initializing node_count only for new nodes. Also, by the way, an if-else statement was removed to simplify the code. Link: https://lkml.kernel.org/r/20230411041005.26205-1-zhangpeng.00@bytedance.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Peng Zhang Cc: Liam R. Howlett Cc: Signed-off-by: Andrew Morton --- lib/maple_tree.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) --- a/lib/maple_tree.c~maple_tree-fix-a-potential-memory-leak-oob-access-or-other-unpredictable-bug +++ a/lib/maple_tree.c @@ -1303,26 +1303,21 @@ static inline void mas_alloc_nodes(struc node = mas->alloc; node->request_count = 0; while (requested) { - max_req = MAPLE_ALLOC_SLOTS; - if (node->node_count) { - unsigned int offset = node->node_count; - - slots = (void **)&node->slot[offset]; - max_req -= offset; - } else { - slots = (void **)&node->slot; - } - + max_req = MAPLE_ALLOC_SLOTS - node->node_count; + slots = (void **)&node->slot[node->node_count]; max_req = min(requested, max_req); count = mt_alloc_bulk(gfp, max_req, slots); if (!count) goto nomem_bulk; + if (node->node_count == 0) { + node->slot[0]->node_count = 0; + node->slot[0]->request_count = 0; + } + node->node_count += count; allocated += count; node = node->slot[0]; - node->node_count = 0; - node->request_count = 0; requested -= count; } mas->alloc->total = allocated; _ Patches currently in -mm which might be from zhangpeng.00@bytedance.com are maple_tree-fix-a-potential-memory-leak-oob-access-or-other-unpredictable-bug.patch mm-kfence-improve-the-performance-of-__kfence_alloc-and-__kfence_free.patch maple_tree-simplify-mas_wr_node_walk.patch maple_tree-use-correct-variable-type-in-sizeof.patch