From patchwork Tue Mar 31 08:59:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 228707 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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 CFD4AC43331 for ; Tue, 31 Mar 2020 09:01:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95D9F20B80 for ; Tue, 31 Mar 2020 09:01:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585645261; bh=i54h0PpoMrZjEXGvANY6FaJbACna+TsoRHILdEn6CI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tzwZZrjgd4AHugRe9DljI1tS0PBDN9vEZYbMxxKls/T1M+NIavf8SkM2MIWYPlPFa AckQiemDdOZpbBbzJgFk7Y+UgbFwCDsp83UWrVqCoVWk+GX5S6Yj8ljvQIi+2AHlEr pAavZI+/4Yyd45fy7Ikd+A9bbEmLcJgdlJMtSegQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730493AbgCaJBA (ORCPT ); Tue, 31 Mar 2020 05:01:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:40050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730490AbgCaJBA (ORCPT ); Tue, 31 Mar 2020 05:01:00 -0400 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 099D720848; Tue, 31 Mar 2020 09:00:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585645259; bh=i54h0PpoMrZjEXGvANY6FaJbACna+TsoRHILdEn6CI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kac2VdeIeEEZNknqs026yMb/tXtTTYrfDn0lu0G/tY7gB741yRzcZiJL2mXHytMVU isKBhUr631iIjJq9/DHOMTmI7KKemYF+4p5gxqURHhdA71rfWj/Uc3FEMyNUr4alk6 3eD4BHXHJfvnK2GtiHKLHCz8pI0AGDBoOfOyUUoE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dafna Hirschfeld , Ezequiel Garcia , Hans Verkuil , Mauro Carvalho Chehab Subject: [PATCH 5.6 23/23] media: v4l2-core: fix a use-after-free bug of sd->devnode Date: Tue, 31 Mar 2020 10:59:35 +0200 Message-Id: <20200331085317.704628095@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200331085308.098696461@linuxfoundation.org> References: <20200331085308.098696461@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dafna Hirschfeld commit 6990570f7e0a6078e11b9c5dc13f4b6e3f49a398 upstream. sd->devnode is released after calling v4l2_subdev_release. Therefore it should be set to NULL so that the subdev won't hold a pointer to a released object. This fixes a reference after free bug in function v4l2_device_unregister_subdev Fixes: 0e43734d4c46e ("media: v4l2-subdev: add release() internal op") Cc: stable@vger.kernel.org Signed-off-by: Dafna Hirschfeld Reviewed-by: Ezequiel Garcia Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/v4l2-core/v4l2-device.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/media/v4l2-core/v4l2-device.c +++ b/drivers/media/v4l2-core/v4l2-device.c @@ -179,6 +179,7 @@ static void v4l2_subdev_release(struct v if (sd->internal_ops && sd->internal_ops->release) sd->internal_ops->release(sd); + sd->devnode = NULL; module_put(owner); }