From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.10]) (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 D7D4B1A3177; Mon, 21 Apr 2025 15:57:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745251078; cv=none; b=fTw989YV9ZmrX5mm49/VOOsqowtqFIN2gaXZWhw9ZWYJr9dlzEFg/Q0HyupA5ipWTiGEZiUHyoW75h5HjQwbl/OyJRzFY2s+RPzn4KlpdU/LeoN6Aaikvdolc9VoxTBlBw15O9M4hmOvlSW1NsQ52hWTloGc1ueodU4wgDwkc9g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745251078; c=relaxed/simple; bh=KrEUT7dHuff1u70nLEWlMRKQ2AKaoUJreC8uWwZYyxI=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=kWl82iCZFcjiosJaTa/O6RpJTxMXh3lKvR9nP+HM7M6P1+F9NbVdezeJaE6eKLZIRPH9vp6K+bXbuCXrQtdO/OfF/zmYwwdTbQixNyA1+ykVBgKpZeWkaNSfb8SFPNmOOeZ1fZ6nFdajRNnnrAztP6LG97GeHW030XFh3z4ih4Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=TjYO10e4; arc=none smtp.client-ip=192.198.163.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="TjYO10e4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1745251077; x=1776787077; h=message-id:date:mime-version:subject:to:references:from: in-reply-to:content-transfer-encoding; bh=KrEUT7dHuff1u70nLEWlMRKQ2AKaoUJreC8uWwZYyxI=; b=TjYO10e44b9HOoeEXfKGmgXTmvgRwRyFG/wbjJzIT7hQfVZHvfwzjNJl aZIdwTaWWQvc6DAxppXZfPmQZe5/NWLxINbv5Wi+1ZLi6ZDAcHcel6mVc H8VGZi9JcsO9EAO7n/lo4/tQZl3Phu69cFKpkqzh9WXNjWu7px2WzlnHH Sdbbc5i4iIfsZysNuMmlqR8kscbW0ODq0iradi5FZcC64TW9K1Ovlw3os Yvp1wtQMrV6NL/C0XM55nbHy+GQAn8OBUNN216eK2nZ+I1WWrYpEil3GX 5DI6sw5K1LPJna3nr+l9rokiI4DpWN6qA973Oy+CHWHrlaXogWGEaRtFB w==; X-CSE-ConnectionGUID: lL1HEYZSS8WxNx4fKUK1xA== X-CSE-MsgGUID: eqYCv522Qtu9Av0Zbhtxag== X-IronPort-AV: E=McAfee;i="6700,10204,11410"; a="58162284" X-IronPort-AV: E=Sophos;i="6.15,228,1739865600"; d="scan'208";a="58162284" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2025 08:57:56 -0700 X-CSE-ConnectionGUID: 0+opOQkoTKWfr+nEWigltw== X-CSE-MsgGUID: yv0Qs9/4TQKnS8o3CDCCJw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,228,1739865600"; d="scan'208";a="136616657" Received: from dnelso2-mobl.amr.corp.intel.com (HELO [10.125.111.68]) ([10.125.111.68]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2025 08:57:56 -0700 Message-ID: <90296464-fec1-4885-a8bb-0f1fd21b6dab@intel.com> Date: Mon, 21 Apr 2025 08:57:54 -0700 Precedence: bulk X-Mailing-List: dmaengine@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1] dmaengine: idxd: Fix allowing write() from different address spaces To: Nathan Lynch , Vinicius Costa Gomes , Vinod Koul , Arjan van de Ven , Nikhil Rao , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250416025201.15753-1-vinicius.gomes@intel.com> <87mscgkuqf.fsf@AUSNATLYNCH.amd.com> Content-Language: en-US From: Dave Jiang In-Reply-To: <87mscgkuqf.fsf@AUSNATLYNCH.amd.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/16/25 8:10 AM, Nathan Lynch wrote: > Vinicius Costa Gomes writes: >> Check if the process submitting the descriptor belongs to the same >> address space as the one that opened the file, reject otherwise. > > I assume this can happen after a fork. > > Do idxd_cdev_mmap() and idxd_cdev_poll() need similar protection? Seems reasonable. Vinicius is on sabbatical. I'll respin his code and add the suggested checks. Thanks Nathan. DJ > >> >> Fixes: 6827738dc684 ("dmaengine: idxd: add a write() method for applications to submit work") >> Signed-off-by: Vinicius Costa Gomes >> --- >> drivers/dma/idxd/cdev.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c >> index ff94ee892339..373c622fcddc 100644 >> --- a/drivers/dma/idxd/cdev.c >> +++ b/drivers/dma/idxd/cdev.c >> @@ -473,6 +473,9 @@ static ssize_t idxd_cdev_write(struct file *filp, const char __user *buf, size_t >> ssize_t written = 0; >> int i; >> >> + if (current->mm != ctx->mm) >> + return -EPERM; >> + >> for (i = 0; i < len/sizeof(struct dsa_hw_desc); i++) { >> int rc = idxd_submit_user_descriptor(ctx, udesc + i); >> >> -- >> 2.49.0