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 0B86234321A for ; Fri, 30 Jan 2026 15:49:08 +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=1769788150; cv=none; b=pka722QBGmzUFT5VVz5xjNseSbLvTQ30dKmnzo1iKWkf7yCsW0fcMIFgSEZCIi7mQOWwh8n6JWkDxOxi5SpmGYUFxDdvYoM4Vbx767iMJWpA+glpYx7gUYaf7IyXqP1k6TmuK/LQA/wYZm//DdfESL85B1Y2d473+BSmZDmBk5s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769788150; c=relaxed/simple; bh=vemaNb9PX2bl5/GL/wA6/rAPx47OHCRjqTk+m3EA9m8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Xcm0TMhdaU3XVs1RmhOHEa+sSl0ju3+wAfdjdwxATV4RpuTOXEK+JXjt2Ax1GvJLDqYf8e/6CqmUGqPzpSLneWzfoi4z6W1dtkCYJ900lMXim29d5wR/W0zwhD42SMlyiUuRqqav0JrGaTyWN1gLmaSJRrJBg/xyJUvEK0FsoKM= 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=TBTzzYeb; 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="TBTzzYeb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1769788148; 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=VDPEdzOpe82L2X5zZrpHHC+ARlFtDRmYGQmS5Pfmouo=; b=TBTzzYebfTjB+WPo3f/87uLYTVs5Qh3ciHuB8nrV1s4ntNViNhvsf+WWm2pKeyi5weP3ak dTIKNfobeArAx5KDqBRTXDfN8zMdoHsowB8OexjeK6HHG42oDvYfaDkP0zm34+WVDFilwx hBvL7258wcKtISodw4TFVfK9Bx1rIQo= Received: from mx-prod-mc-08.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-161-t8Zt0CR9NVmP-MbXZPDD7Q-1; Fri, 30 Jan 2026 10:49:04 -0500 X-MC-Unique: t8Zt0CR9NVmP-MbXZPDD7Q-1 X-Mimecast-MFC-AGG-ID: t8Zt0CR9NVmP-MbXZPDD7Q_1769788143 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D93E718E7C2D; Fri, 30 Jan 2026 15:48:48 +0000 (UTC) Received: from fedora (unknown [10.72.116.182]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 821233008DDF; Fri, 30 Jan 2026 15:48:44 +0000 (UTC) Date: Fri, 30 Jan 2026 23:48:38 +0800 From: Ming Lei To: Caleb Sander Mateos Cc: Jens Axboe , Govindarajulu Varadarajan , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] ublk: don't write to struct ublksrv_ctrl_cmd Message-ID: References: <20260129224618.975401-1-csander@purestorage.com> <20260129224618.975401-3-csander@purestorage.com> 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=us-ascii Content-Disposition: inline In-Reply-To: <20260129224618.975401-3-csander@purestorage.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 On Thu, Jan 29, 2026 at 03:46:15PM -0700, Caleb Sander Mateos wrote: > ublk_ctrl_uring_cmd_permission() writes to struct ublksrv_ctrl_cmd's > addr and len fields, which is racy because ublksrv_ctrl_cmd is part of > the io_uring_sqe, which may lie in userspace-mapped memory. Store the > values of addr in len in local variables instead to avoid the race. > > Fixes: 87213b0d847c ("ublk: allow non-blocking ctrl cmds in IO_URING_F_NONBLOCK issue") > Signed-off-by: Caleb Sander Mateos The simpler approach is to define local `header` variable and copy data to it. Given it is introduced in v6.19-rc1, backport should be easy, so this patch looks fine: Reviewed-by: Ming Lei Thanks, Ming