From patchwork Tue Dec 1 15:19:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 343896 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=-10.6 required=3.0 tests=BAYES_00, DATE_IN_PAST_96_XX, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 3C198C2BB48 for ; Mon, 14 Dec 2020 21:08:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12C5622525 for ; Mon, 14 Dec 2020 21:08:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2503585AbgLNVIR (ORCPT ); Mon, 14 Dec 2020 16:08:17 -0500 Received: from www.linuxtv.org ([130.149.80.248]:52236 "EHLO www.linuxtv.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2503637AbgLNVIR (ORCPT ); Mon, 14 Dec 2020 16:08:17 -0500 Received: from mchehab by www.linuxtv.org with local (Exim 4.92) (envelope-from ) id 1kov46-0039g2-3R; Mon, 14 Dec 2020 21:07:30 +0000 From: Mauro Carvalho Chehab Date: Tue, 01 Dec 2020 15:19:07 +0000 Subject: [git:media_tree/master] media: pulse8-cec: fix duplicate free at disconnect or probe error To: linuxtv-commits@linuxtv.org Cc: Maxime Ripard , stable@vger.kernel.org, Hans Verkuil Mail-followup-to: linux-media@vger.kernel.org Forward-to: linux-media@vger.kernel.org Reply-to: linux-media@vger.kernel.org Message-Id: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is an automatic generated email to let you know that the following patch were queued: Subject: media: pulse8-cec: fix duplicate free at disconnect or probe error Author: Hans Verkuil Date: Fri Nov 27 10:36:32 2020 +0100 Commit 601282d65b96 ("media: pulse8-cec: use adap_free callback") used the adap_free callback to clean up on disconnect. What I forgot was that in the probe it will call cec_delete_adapter() followed by kfree(pulse8) if an error occurs. But by using the adap_free callback, cec_delete_adapter() is already freeing the pulse8 struct. This wasn't noticed since normally the probe works fine, but Pulse-Eight published a new firmware version that caused a probe error, so now it hits this bug. This affects firmware version 12, but probably any version >= 10. Commit aa9eda76129c ("media: pulse8-cec: close serio in disconnect, not adap_free") made this worse by adding the line 'pulse8->serio = NULL' right after the call to cec_unregister_adapter in the disconnect() function. Unfortunately, cec_unregister_adapter will typically call cec_delete_adapter (unless a filehandle to the cec device is still open), which frees the pulse8 struct. So now it will also crash on a simple unplug of the Pulse-Eight device. With this fix both the unplug issue and a probe() error situation are handled correctly again. It will still fail to probe() with a v12 firmware, that's something to look at separately. Signed-off-by: Hans Verkuil Reported-by: Maxime Ripard Tested-by: Maxime Ripard Fixes: aa9eda76129c ("media: pulse8-cec: close serio in disconnect, not adap_free") Fixes: 601282d65b96 ("media: pulse8-cec: use adap_free callback") Cc: Signed-off-by: Mauro Carvalho Chehab drivers/media/cec/usb/pulse8/pulse8-cec.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/media/cec/usb/pulse8/pulse8-cec.c b/drivers/media/cec/usb/pulse8/pulse8-cec.c index e4d8446b87da..5d3a3f775bc8 100644 --- a/drivers/media/cec/usb/pulse8/pulse8-cec.c +++ b/drivers/media/cec/usb/pulse8/pulse8-cec.c @@ -650,7 +650,6 @@ static void pulse8_disconnect(struct serio *serio) struct pulse8 *pulse8 = serio_get_drvdata(serio); cec_unregister_adapter(pulse8->adap); - pulse8->serio = NULL; serio_set_drvdata(serio, NULL); serio_close(serio); } @@ -830,8 +829,10 @@ static int pulse8_connect(struct serio *serio, struct serio_driver *drv) pulse8->adap = cec_allocate_adapter(&pulse8_cec_adap_ops, pulse8, dev_name(&serio->dev), caps, 1); err = PTR_ERR_OR_ZERO(pulse8->adap); - if (err < 0) - goto free_device; + if (err < 0) { + kfree(pulse8); + return err; + } pulse8->dev = &serio->dev; serio_set_drvdata(serio, pulse8); @@ -874,8 +875,6 @@ close_serio: serio_close(serio); delete_adap: cec_delete_adapter(pulse8->adap); -free_device: - kfree(pulse8); return err; }