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=-18.8 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, 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 478BBC43603 for ; Mon, 12 Apr 2021 08:55:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20AEE61363 for ; Mon, 12 Apr 2021 08:55:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238694AbhDLIy3 (ORCPT ); Mon, 12 Apr 2021 04:54:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:41562 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238386AbhDLIto (ORCPT ); Mon, 12 Apr 2021 04:49:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4B9196134F; Mon, 12 Apr 2021 08:48:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618217318; bh=6Fc8ckiUHHGh0g3X7q9XcyLVQovvOE71j30AJIPnx+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BDiVwdgSR2PvXh03qlym3t2Idjy/rNe0DqHuS2uQygDIT3tSQHyMTgHzal4Wbx1+e tpsgSA283e1k+bGVCYIByIGA17MmMysbI9NVwHdDnVY9d1wkIcDF19XZGFvVsTz2VP EJOrd8x91oiQsmjSVFsgnZPjiHVLxYn70UgEmRic= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukasz Majczak , Lukasz Bartosik , Stephen Boyd , Sasha Levin Subject: [PATCH 5.4 082/111] clk: fix invalid usage of list cursor in register Date: Mon, 12 Apr 2021 10:41:00 +0200 Message-Id: <20210412084006.996685814@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210412084004.200986670@linuxfoundation.org> References: <20210412084004.200986670@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lukasz Bartosik [ Upstream commit 8d3c0c01cb2e36b2bf3c06a82b18b228d0c8f5d0 ] Fix invalid usage of a list_for_each_entry cursor in clk_notifier_register(). When list is empty or if the list is completely traversed (without breaking from the loop on one of the entries) then the list cursor does not point to a valid entry and therefore should not be used. The issue was dicovered when running 5.12-rc1 kernel on x86_64 with KASAN enabled: BUG: KASAN: global-out-of-bounds in clk_notifier_register+0xab/0x230 Read of size 8 at addr ffffffffa0d10588 by task swapper/0/1 CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc1 #1 Hardware name: Google Caroline/Caroline, BIOS Google_Caroline.7820.430.0 07/20/2018 Call Trace: dump_stack+0xee/0x15c print_address_description+0x1e/0x2dc kasan_report+0x188/0x1ce ? clk_notifier_register+0xab/0x230 ? clk_prepare_lock+0x15/0x7b ? clk_notifier_register+0xab/0x230 clk_notifier_register+0xab/0x230 dw8250_probe+0xc01/0x10d4 ... Memory state around the buggy address: ffffffffa0d10480: 00 00 00 00 00 03 f9 f9 f9 f9 f9 f9 00 00 00 00 ffffffffa0d10500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 >ffffffffa0d10580: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffffffffa0d10600: 00 00 00 00 00 00 f9 f9 f9 f9 f9 f9 00 00 00 00 ffffffffa0d10680: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00 ================================================================== Fixes: b2476490ef11 ("clk: introduce the common clock framework") Reported-by: Lukasz Majczak Signed-off-by: Lukasz Bartosik Link: https://lore.kernel.org/r/20210401225149.18826-1-lb@semihalf.com Signed-off-by: Stephen Boyd Signed-off-by: Sasha Levin --- drivers/clk/clk.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 36e9f38a3882..5db91903d02b 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -4151,20 +4151,19 @@ int clk_notifier_register(struct clk *clk, struct notifier_block *nb) /* search the list of notifiers for this clk */ list_for_each_entry(cn, &clk_notifier_list, node) if (cn->clk == clk) - break; + goto found; /* if clk wasn't in the notifier list, allocate new clk_notifier */ - if (cn->clk != clk) { - cn = kzalloc(sizeof(*cn), GFP_KERNEL); - if (!cn) - goto out; + cn = kzalloc(sizeof(*cn), GFP_KERNEL); + if (!cn) + goto out; - cn->clk = clk; - srcu_init_notifier_head(&cn->notifier_head); + cn->clk = clk; + srcu_init_notifier_head(&cn->notifier_head); - list_add(&cn->node, &clk_notifier_list); - } + list_add(&cn->node, &clk_notifier_list); +found: ret = srcu_notifier_chain_register(&cn->notifier_head, nb); clk->core->notifier_count++; -- 2.30.2