From patchwork Sat Apr 15 16:07:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 673558 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 E2301C77B70 for ; Sat, 15 Apr 2023 16:08:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230058AbjDOQI2 (ORCPT ); Sat, 15 Apr 2023 12:08:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229848AbjDOQI1 (ORCPT ); Sat, 15 Apr 2023 12:08:27 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3967419BB for ; Sat, 15 Apr 2023 09:07:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681574862; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HO3NR1jjOy2hneBq8NSWJ2zq3Oxl9rsO1Sm5Zmq2dqA=; b=ZaXaZ2mSiyBQZviHVEBLT84uGCOosmqixiQMRaAswcWvpcFMcBnYx1FPSgV26Gq5sDoau+ Fj1RF7xT4+HIJZrxvxu5u32GYHUJIyoXEgU2RbpaTJzwBxkDvi4i89ETKxNm27QfKtpcJ4 bVaQI1K7D8p6beuUbmGYHHEOxbQr0KI= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-447-WIy5dPSTMO6t-14EmjMuOA-1; Sat, 15 Apr 2023 12:07:41 -0400 X-MC-Unique: WIy5dPSTMO6t-14EmjMuOA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B2A533C0F662; Sat, 15 Apr 2023 16:07:40 +0000 (UTC) Received: from shalem.redhat.com (unknown [10.39.192.15]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8AE912166B26; Sat, 15 Apr 2023 16:07:38 +0000 (UTC) From: Hans de Goede To: Sebastian Reichel Cc: Hans de Goede , laji Xiao <3252204392abc@gmail.com>, linux-pm@vger.kernel.org, stable@vger.kernel.org, Marek Vasut Subject: [PATCH 3/6] power: supply: bq25890: Fix external_power_changed race Date: Sat, 15 Apr 2023 18:07:31 +0200 Message-Id: <20230415160734.70475-4-hdegoede@redhat.com> In-Reply-To: <20230415160734.70475-1-hdegoede@redhat.com> References: <20230415160734.70475-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org bq25890_charger_external_power_changed() dereferences bq->charger, which gets sets in bq25890_power_supply_init() like this: bq->charger = devm_power_supply_register(bq->dev, &bq->desc, &psy_cfg); As soon as devm_power_supply_register() has called device_add() the external_power_changed callback can get called. So there is a window where bq25890_charger_external_power_changed() may get called while bq->charger has not been set yet leading to a NULL pointer dereference. This race hits during boot sometimes on a Lenovo Yoga Book 1 yb1-x90f when the cht_wcove_pwrsrc (extcon) power_supply is done with detecting the connected charger-type which happens to exactly hit the small window: BUG: kernel NULL pointer dereference, address: 0000000000000018 RIP: 0010:__power_supply_is_supplied_by+0xb/0xb0 Call Trace: __power_supply_get_supplier_property+0x19/0x50 class_for_each_device+0xb1/0xe0 power_supply_get_property_from_supplier+0x2e/0x50 bq25890_charger_external_power_changed+0x38/0x1b0 [bq25890_charger] __power_supply_changed_work+0x30/0x40 class_for_each_device+0xb1/0xe0 power_supply_changed_work+0x5f/0xe0 Fixing this is easy. The external_power_changed callback gets passed the power_supply which will eventually get stored in bq->charger, so bq25890_charger_external_power_changed() can simply directly use the passed in psy argument which is always valid. Fixes: eab25b4f93aa ("power: supply: bq25890: On the bq25892 set the IINLIM based on external charger detection") Cc: stable@vger.kernel.org Cc: Marek Vasut Signed-off-by: Hans de Goede --- drivers/power/supply/bq25890_charger.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/power/supply/bq25890_charger.c b/drivers/power/supply/bq25890_charger.c index 794512285629..0157713a7e7c 100644 --- a/drivers/power/supply/bq25890_charger.c +++ b/drivers/power/supply/bq25890_charger.c @@ -750,7 +750,7 @@ static void bq25890_charger_external_power_changed(struct power_supply *psy) if (bq->chip_version != BQ25892) return; - ret = power_supply_get_property_from_supplier(bq->charger, + ret = power_supply_get_property_from_supplier(psy, POWER_SUPPLY_PROP_USB_TYPE, &val); if (ret)