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=-5.2 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_MUTT 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 E3BCEC31E45 for ; Thu, 13 Jun 2019 15:51:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B83A520851 for ; Thu, 13 Jun 2019 15:51:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560441107; bh=x6g8SpdX2s4hgnOzlEqiNhMKdDtcVuerNEHpNk2rrmI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=nApVm9l08402tQKTbBkisaztOuFU4sMMa2+c97LGliVAy/OXv8zQ8qfj90upWiBnZ CaAURbXmxsh8UsS4UZjUJcCILQpYYXUuKSHYCTUM6dR9t6+ke50eQ8JpXYMwY5FU6r Hp0TzuCxz9Ytj2ZBojTUD6YtfJ2JJTK3xb3yPczI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387412AbfFMPvp (ORCPT ); Thu, 13 Jun 2019 11:51:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:44794 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731659AbfFMJL0 (ORCPT ); Thu, 13 Jun 2019 05:11:26 -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 199922133D; Thu, 13 Jun 2019 09:11:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560417085; bh=x6g8SpdX2s4hgnOzlEqiNhMKdDtcVuerNEHpNk2rrmI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uTZL4pHjJOw7s/bprqy0krU4/Onto+EUdmkGYsEHNey88pVk2tB0UidD45l7fPpTp LEuaNYkdd3tG9SHhffzcXQ/0B2ERGtQTvo2bWIMeqM9EbfqjP9e07ltsVpzrFcDYAx 7illd/oKz/AQSJo3ByZi7LPB8aBsqCF4lNhXqzkg= Date: Thu, 13 Jun 2019 11:11:22 +0200 From: Greg Kroah-Hartman To: Takashi Iwai Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, syzbot+e4c8abb920efa77bace9@syzkaller.appspotmail.com, Sasha Levin Subject: Re: [PATCH 4.14 61/81] ALSA: seq: Protect in-kernel ioctl calls with mutex Message-ID: <20190613091122.GA31122@kroah.com> References: <20190613075649.074682929@linuxfoundation.org> <20190613075653.581995283@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 13, 2019 at 11:02:54AM +0200, Takashi Iwai wrote: > On Thu, 13 Jun 2019 10:33:44 +0200, > Greg Kroah-Hartman wrote: > > > > [ Upstream commit feb689025fbb6f0aa6297d3ddf97de945ea4ad32 ] > > > > ALSA OSS sequencer calls the ioctl function indirectly via > > snd_seq_kernel_client_ctl(). While we already applied the protection > > against races between the normal ioctls and writes via the client's > > ioctl_mutex, this code path was left untouched. And this seems to be > > the cause of still remaining some rare UAF as spontaneously triggered > > by syzkaller. > > > > For the sake of robustness, wrap the ioctl_mutex also for the call via > > snd_seq_kernel_client_ctl(), too. > > > > Reported-by: syzbot+e4c8abb920efa77bace9@syzkaller.appspotmail.com > > Signed-off-by: Takashi Iwai > > Signed-off-by: Sasha Levin > > This commit is reverted later by commit f0654ba94e33. > So please drop this. The proper fix is done later by commit > 7c32ae35fbf9 ("ALSA: seq: Cover unsubscribe_port() in list_mutex") > > Ditto for 4.19.y and 5.1.y. Now dropped everywhere, and I added 7c32ae35fbf9 ("ALSA: seq: Cover unsubscribe_port() in list_mutex") everywhere instead. thanks, greg k-h