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, 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 EBF52C4361A for ; Mon, 5 Apr 2021 09:05:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2442613A5 for ; Mon, 5 Apr 2021 09:05:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238300AbhDEJEo (ORCPT ); Mon, 5 Apr 2021 05:04:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:46768 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237715AbhDEJDi (ORCPT ); Mon, 5 Apr 2021 05:03:38 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2782E610E8; Mon, 5 Apr 2021 09:03:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617613411; bh=NbXGtagGC6nta9wmmqR4lJoh5XClR+lCZLLHV+MV860=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m0OgbeR+adT1dLEUPvTpy8odH+26InhqyN9nLzCdGb7ChBW1zJ6qOVcsPjQlEroND h1YmbYuG07WDhoFnDn2h/lVJ/MmvX5VP7jUFGYtJUUYzaVIZ2lBDjOl54le2Mo16OY YBVXAP/vKJDMud5/rJkQybuGDhqQoJJFMmh0Brro= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Manaf Meethalavalappu Pallikunhi , Daniel Lezcano , Sasha Levin Subject: [PATCH 5.4 27/74] thermal/core: Add NULL pointer check before using cooling device stats Date: Mon, 5 Apr 2021 10:53:51 +0200 Message-Id: <20210405085025.610680211@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210405085024.703004126@linuxfoundation.org> References: <20210405085024.703004126@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: Manaf Meethalavalappu Pallikunhi [ Upstream commit 2046a24ae121cd107929655a6aaf3b8c5beea01f ] There is a possible chance that some cooling device stats buffer allocation fails due to very high cooling device max state value. Later cooling device update sysfs can try to access stats data for the same cooling device. It will lead to NULL pointer dereference issue. Add a NULL pointer check before accessing thermal cooling device stats data. It fixes the following bug [ 26.812833] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004 [ 27.122960] Call trace: [ 27.122963] do_raw_spin_lock+0x18/0xe8 [ 27.122966] _raw_spin_lock+0x24/0x30 [ 27.128157] thermal_cooling_device_stats_update+0x24/0x98 [ 27.128162] cur_state_store+0x88/0xb8 [ 27.128166] dev_attr_store+0x40/0x58 [ 27.128169] sysfs_kf_write+0x50/0x68 [ 27.133358] kernfs_fop_write+0x12c/0x1c8 [ 27.133362] __vfs_write+0x54/0x160 [ 27.152297] vfs_write+0xcc/0x188 [ 27.157132] ksys_write+0x78/0x108 [ 27.162050] ksys_write+0xf8/0x108 [ 27.166968] __arm_smccc_hvc+0x158/0x4b0 [ 27.166973] __arm_smccc_hvc+0x9c/0x4b0 [ 27.186005] el0_svc+0x8/0xc Signed-off-by: Manaf Meethalavalappu Pallikunhi Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/1607367181-24589-1-git-send-email-manafm@codeaurora.org Signed-off-by: Sasha Levin --- drivers/thermal/thermal_sysfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c index aa99edb4dff7..4dce4a8f71ed 100644 --- a/drivers/thermal/thermal_sysfs.c +++ b/drivers/thermal/thermal_sysfs.c @@ -770,6 +770,9 @@ void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev, { struct cooling_dev_stats *stats = cdev->stats; + if (!stats) + return; + spin_lock(&stats->lock); if (stats->state == new_state) -- 2.30.1