From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794272196; b=OroXJxArkijZ61Ctc25n+YpQg5wRoSaaUQWN56pnHI0Ia8pJEc969Oaxk1iAJlz8w15i /VLIB2AqzGo4YiDx6J+NKSx/pl29U7YmYxyid01GiTJSPm58D8YwSl1Pg1OluzxUvC6Ro CQyAwYksTfLsylqojttlDT63T2hV2tkswHVZeFEZexBsl7VAIK5rI8c0synV7jb96sho4 V+QkBT0LIYSpp6c3YTnEg4ADWY+acwafLS1RRdb3t+lknnHaW6BMkSndoZXun6F9IYTvH lhh2qOTs3xfVItC1rM5c7YLebmUhcBFcWf7KmpbDW/kU39yaIXG6WkYYLwslKfDmw8Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794272196; h=Received:DKIM-Signature:Date:From:To:cc:Subject:In-Reply-To: Message-ID:References:MIME-Version:Content-Type; bh=POYNQ8UFORjsZSBOAZpmVOdf956zxHeg9590atUMmfM=; b=4Jw8fOy7aZTLt8ueMTuh07gfyMC8HAXWd5gOATwS+/kmJ2h2vTXa9Cbp3+n0hoW+ZZeU suSF41DMLmd5urazu576vPLDBhgu7B8zKfmPQSKTtrsOArHlvdVooHFs6o3+mkst4PJuT KezqMmdXaj4TU2P6oa+mCIW14pre71WootUI5n9Q8iTmniFVpPD/G1UvqqCkAKNooCav1 iHrVlXz09gyC+nQ3jZOLBlgSIzHOtfgqgXdsmRMBVPhhTjK5dEooqemnN+MsUCNs5E2fc /Cxy2H9eo+AxOVEZi1TQyl+EsE2yKHBG7KstO/MkQemNERC82zTkNg7MJXAdGZtowOQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="DLwdMFW/"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED637606A32A; Tue, 10 Nov 2026 00:56:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=DLwdMFW/ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 76F921F008A1; Tue, 10 Nov 2026 00:56:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794272195; bh=POYNQ8UFORjsZSBOAZpmVOdf956zxHeg9590atUMmfM=; h=Date:From:To:cc:Subject:In-Reply-To:References; b=DLwdMFW/60LVnTLa0yQmFg0tJx5vXiCHVmG3eQvGbHS3Idmk3+SseDFBk4e4QF6db QGhyDVdv2TP7uE6I7XG/AK58MazhLRnlCZ5IuW+IA6DhA5bLWD/ACaImWurFZy0tQz lG0sil3FGULB2pGRmHFZtabyVEjLG1JEgXDwUhr7Ds+JfrM4HvX/XQnnIh6+HycLwT PjlB5wVDGsd8SFJO8h51aceVX/oB5ajpAbcSzJ1OiF2SPzAMsPLPlO4hwHFHxz2rJF tOrhtc7ad9zvKgBlPUII/yBcXSRUtAqULMSVRHxrRdbVxmN/lbj6eJxUfYj0lJyQdy SPIVp3mRgcmJA== Date: Mon, 9 Nov 2026 16:56:33 -0800 (PST) From: Stefano Stabellini To: Yehyeong Lee cc: jgross@suse.com, sstabellini@kernel.org, oleksandr_tyshchenko@epam.com, boris.ostrovsky@oracle.com, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 2/2] xen/pvcalls: destroy the per-socket workqueue on release In-Reply-To: <20261109122324.30134-3-yhlee@isslab.korea.ac.kr> Message-ID: <604a9832-80ac-107c-b36f-4bb338519cbc@kernel.org> References: <20261109122324.30134-1-yhlee@isslab.korea.ac.kr> <20261109122324.30134-3-yhlee@isslab.korea.ac.kr> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Mon, 9 Nov 2026, Yehyeong Lee wrote: > pvcalls_new_active_socket() gives every active socket its own ordered > workqueue: > > map->ioworker.wq = alloc_ordered_workqueue("pvcalls_io", 0); > > and nothing ever destroys it. pvcalls_back_release_active() flushes > map->ioworker.register_work and frees map, but the workqueue and its > pool_workqueues stay allocated, so a frontend leaks a workqueue per socket > it connects and releases - a loop a guest can run as long as it likes. > > Destroy it after the IRQ is unbound, so no new work can be queued, and > before map is freed. pvcalls_back_ioworker() takes no locks, in > particular not fedata->socket_lock, which the backend_disconnect() caller > holds here, so draining it from this point is safe; the flush_work() just > above already has the same requirement. > > Fixes: 5db4d286a8ef ("xen/pvcalls: implement connect command") > Cc: stable@vger.kernel.org > Signed-off-by: Yehyeong Lee > --- > drivers/xen/pvcalls-back.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c > index dcefa91a40cd05..27aa06289a7b92 100644 > --- a/drivers/xen/pvcalls-back.c > +++ b/drivers/xen/pvcalls-back.c > @@ -456,6 +456,7 @@ static int pvcalls_back_release_active(struct xenbus_device *dev, > xenbus_unmap_ring_vfree(dev, map->bytes); > xenbus_unmap_ring_vfree(dev, (void *)map->ring); > unbind_from_irqhandler(map->irq, map); > + destroy_workqueue(map->ioworker.wq); Please move the call to destroy_workqueue() just after flush_work(). With that: Reviewed-by: Stefano Stabellini > sock_release(map->sock); > kfree(map); > -- > 2.43.0 >