From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8E8CE22AE65 for ; Mon, 12 Jan 2026 05:40:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768196436; cv=none; b=diN1jvVoOjBTSnJjE4lKE/oNnaFm4HFVNGhskbSVUN4PN1L9rh+HtD3E78Brn632/DfSysBwo5YIlOTfPs32wO/vP1fAV9eLE3JakjKi7KWk1cAMQVFHmEp1kETEVhVyE+Bs6/ZYe+usA5UuBjLws4nWUDEGzGbJtb8u0o0hMjU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768196436; c=relaxed/simple; bh=PHw/+BMzpdwZVAyAXhbv02n447R+EAZTmHifaichADU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=l81WZSzMh9k7PzD84hON7aZ7dtA8Kv9MPBGFuJ2hR2Cwe+D3XA+AHRDadZjGETtBx9QRH1FfGpU7qmKtS58kwXSXw79hJYqrB1mWkH34HjIUPYqumz3Ohh1UjCQqQQQbUwVwsuCPZ6XO2INiZFK+WoS6Fz5J+ePjjqXEhsKLXv0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Jamh9ApZ; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Jamh9ApZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1768196434; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ch0WtTqfAzSn33u9u9LW5lpCUVUydnD/jEupG2LR628=; b=Jamh9ApZN/E5HTvP1bfl4OqLcIfnFVVEbgrThZTvYyU3Ij/1gfq5OxaXY2hT6Qs+LIfYf2 5fx5Tj5kbKofbYgXB7dZuP0H9H535DYlse2rrDEY3AKdk5t/JSlNRDHwks98LoYqlX8kgM sMZLKAxyYzMOqIshZxl1IUF4ZIPRrKA= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-83-OD1ykJJEMQi8oKFGjzBW-Q-1; Mon, 12 Jan 2026 00:40:30 -0500 X-MC-Unique: OD1ykJJEMQi8oKFGjzBW-Q-1 X-Mimecast-MFC-AGG-ID: OD1ykJJEMQi8oKFGjzBW-Q_1768196429 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5DB8218005A7; Mon, 12 Jan 2026 05:40:29 +0000 (UTC) Received: from fedora (unknown [10.72.116.42]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9D2121800665; Mon, 12 Jan 2026 05:40:25 +0000 (UTC) Date: Mon, 12 Jan 2026 13:40:20 +0800 From: Ming Lei To: Seamus Connor Cc: Jens Axboe , linux-block@vger.kernel.org, Caleb Sander , linux-kernel@vger.kernel.org Subject: Re: [PATCH] ublk: fix ublksrv pid handling for pid namespaces Message-ID: References: Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On Sat, Jan 10, 2026 at 04:00:15PM -0800, Seamus Connor wrote: > When ublksrv runs inside a pid namespace, START/END_RECOVERY compared > the stored init-ns tgid against the userspace pid (getpid vnr), so the > check failed and control ops could not proceed. Compare against the > caller’s init-ns tgid and store that value, then translate it back to > the caller’s pid namespace when reporting GET_DEV_INFO so ublk list > shows a sensible pid. > > Testing: start/recover in a pid namespace; `ublk list` shows > reasonable pid values in init, child, and sibling namespaces. > > Fixes: d37a224fc119 ("ublk: validate ublk server pid") > Signed-off-by: Seamus Connor > Reviewed-by: Caleb Sander Mateos > --- > drivers/block/ublk_drv.c | 36 ++++++++++++++++++++++++++---------- > 1 file changed, 26 insertions(+), 10 deletions(-) > > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c > index 79847e0b9e88..9ef6432fef7c 100644 > --- a/drivers/block/ublk_drv.c > +++ b/drivers/block/ublk_drv.c > @@ -2858,7 +2858,6 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, > const struct ublksrv_ctrl_cmd *header) > { > const struct ublk_param_basic *p = &ub->params.basic; > - int ublksrv_pid = (int)header->data[0]; > struct queue_limits lim = { > .logical_block_size = 1 << p->logical_bs_shift, > .physical_block_size = 1 << p->physical_bs_shift, > @@ -2874,8 +2873,6 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, > struct gendisk *disk; > int ret = -EINVAL; > > - if (ublksrv_pid <= 0) > - return -EINVAL; > if (!(ub->params.types & UBLK_PARAM_TYPE_BASIC)) > return -EINVAL; > > @@ -2922,7 +2919,7 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, > if (wait_for_completion_interruptible(&ub->completion) != 0) > return -EINTR; > > - if (ub->ublksrv_tgid != ublksrv_pid) > + if (ub->ublksrv_tgid != current->tgid) This way requires that START_DEV command can only be submitted from ublk server daemon context, which may break implementation sending `START_DEV` command from remote process context. Can we fix it in the following way? + struct pid *pid = find_vpid(ublksrv_pid); + + if (!pid || pid_nr(pid) != ub->ublksrv_tgid) + return -EINVAL; Also your patch has patch style issue, please check it before posting out by `./scripts/checkpatch.pl`. Or you may have to use `git send-email` to send patch file. Thanks, Ming