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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 76792C433ED for ; Tue, 4 May 2021 07:29:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 424AA611CB for ; Tue, 4 May 2021 07:29:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229806AbhEDHaf (ORCPT ); Tue, 4 May 2021 03:30:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:20742 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229607AbhEDHae (ORCPT ); Tue, 4 May 2021 03:30:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620113380; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=EWr6gsC5qADDiQYYPg2fD6vVefc5Po56DpnCBdNM/7A=; b=GHlI3YJrDeWno7jXXT36q2GTt/uOxm0mvb9WM3jQGPRevwm5mSZ96a/kT9o2NZm9LEQB2r OKbgzWoKhuWh/p6or0cRZ+81VS8bYPe1cIchajyKoMsmCGKE94gJuYqe8r1WIwQ018XJG0 IY7/B2mxBiXnC53R2BedJFW+Ul0qcxk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-458-NBwn1mh9Mh-_oI_8pKvq7w-1; Tue, 04 May 2021 03:29:36 -0400 X-MC-Unique: NBwn1mh9Mh-_oI_8pKvq7w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D68A5800D62; Tue, 4 May 2021 07:29:34 +0000 (UTC) Received: from T590 (ovpn-12-77.pek2.redhat.com [10.72.12.77]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A6A6060C5C; Tue, 4 May 2021 07:29:27 +0000 (UTC) Date: Tue, 4 May 2021 15:29:22 +0800 From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Bart Van Assche , Khazhy Kumykov , Shin'ichiro Kawasaki , Hannes Reinecke , John Garry , David Jeffery Subject: Re: [PATCH V4 0/4] blk-mq: fix request UAF related with iterating over tagset requests Message-ID: References: <20210429023458.3044317-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210429023458.3044317-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Apr 29, 2021 at 10:34:54AM +0800, Ming Lei wrote: > Hi Jens, > > This patchset fixes the request UAF issue by one simple approach, > without clearing ->rqs[] in fast path. > > 1) grab request's ref before calling ->fn in blk_mq_tagset_busy_iter, > and release it after calling ->fn, so ->fn won't be called for one > request if its queue is frozen, done in 2st patch > > 2) clearing any stale request referred in ->rqs[] before freeing the > request pool, one per-tags spinlock is added for protecting > grabbing request ref vs. clearing ->rqs[tag], so UAF by refcount_inc_not_zero > in bt_tags_iter() is avoided, done in 3rd patch. > > > V4: > - remove hctx->fq-flush_rq from tags->rqs[] before freeing hw queue, > patch 4/4 is added, which is based on David's patch. Hello Jens, Any chance to merge the patch to 5.13 if you are fine? Thanks, Ming