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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 BA825C3276C for ; Thu, 2 Jan 2020 22:29:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AECD21835 for ; Thu, 2 Jan 2020 22:29:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004166; bh=TgdWmQUysGVNSA1T+dSHQ4fElPOLvT415pV5yyln5QQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AbMG0NBAsXBOBL9AkSi6/xQWNtcfCINQZC9SHeeNzd/CUlQxl6BSa2bpHB5IS+xf7 1jKtFeE8Csjl7Zc0nC+i6OVpusiigeQl5eU70pVBpdBAS96QM2JnKGDbo3OFkTKO1k Pt3ojAyjfd75S/78u0doE8i7t+E/BSSs0jOTX6zg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730043AbgABW3Z (ORCPT ); Thu, 2 Jan 2020 17:29:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:60342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730020AbgABW3W (ORCPT ); Thu, 2 Jan 2020 17:29:22 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E22A620866; Thu, 2 Jan 2020 22:29:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004162; bh=TgdWmQUysGVNSA1T+dSHQ4fElPOLvT415pV5yyln5QQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ute1wTi40mTh/7V1S/0zwG2n2lK+3q3D7KM1A8wEKEln7q9fl98rOQsKt/VNptOea Q/1hEoBJRrG0YOO2PrEKbmCKjSC7hh9bh3rGB0Mnm7VupMhCRMuui10vB7hp3TQI48 7YqTInutlgApW0/kv+NGAV88R2YoW3hB+z5g6o8M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mike Isely , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.9 063/171] media: pvrusb2: Fix oops on tear-down when radio support is not present Date: Thu, 2 Jan 2020 23:06:34 +0100 Message-Id: <20200102220555.616782506@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102220546.960200039@linuxfoundation.org> References: <20200102220546.960200039@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mike Isely [ Upstream commit 7f404ae9cf2a285f73b3c18ab9303d54b7a3d8e1 ] In some device configurations there's no radio or radio support in the driver. That's OK, as the driver sets itself up accordingly. However on tear-down in these caes it's still trying to tear down radio related context when there isn't anything there, leading to dereferences through a null pointer and chaos follows. How this bug survived unfixed for 11 years in the pvrusb2 driver is a mystery to me. [hverkuil: fix two checkpatch warnings] Signed-off-by: Mike Isely Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/pvrusb2/pvrusb2-v4l2.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c b/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c index 2cc4d2b6f810..d18ced28797d 100644 --- a/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c +++ b/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c @@ -919,8 +919,12 @@ static void pvr2_v4l2_internal_check(struct pvr2_channel *chp) pvr2_v4l2_dev_disassociate_parent(vp->dev_video); pvr2_v4l2_dev_disassociate_parent(vp->dev_radio); if (!list_empty(&vp->dev_video->devbase.fh_list) || - !list_empty(&vp->dev_radio->devbase.fh_list)) + (vp->dev_radio && + !list_empty(&vp->dev_radio->devbase.fh_list))) { + pvr2_trace(PVR2_TRACE_STRUCT, + "pvr2_v4l2 internal_check exit-empty id=%p", vp); return; + } pvr2_v4l2_destroy_no_lock(vp); } @@ -994,7 +998,8 @@ static int pvr2_v4l2_release(struct file *file) kfree(fhp); if (vp->channel.mc_head->disconnect_flag && list_empty(&vp->dev_video->devbase.fh_list) && - list_empty(&vp->dev_radio->devbase.fh_list)) { + (!vp->dev_radio || + list_empty(&vp->dev_radio->devbase.fh_list))) { pvr2_v4l2_destroy_no_lock(vp); } return 0; -- 2.20.1