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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8F61DCF6499 for ; Mon, 30 Sep 2024 11:20:38 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 46BD810E3E7; Mon, 30 Sep 2024 11:20:38 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="tO+PK3cm"; dkim-atps=neutral Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by gabe.freedesktop.org (Postfix) with ESMTPS id 54AD710E034 for ; Mon, 30 Sep 2024 11:20:37 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 768895C2B52; Mon, 30 Sep 2024 11:20:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B550C4CEC7; Mon, 30 Sep 2024 11:20:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727695236; bh=D34FnNso2mKyPNtD5emxnQNZ3judy8F+Azic7aL00nA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tO+PK3cmdfy9L3eXnGb+iUvjClDBDwYQPntgvSbnZc7GTJ6m93fuAhJoWuu9J/2MH 2Ds047ggO3Idju6tMUzDu7hrbGuosWAXMJHNbokooYSxM+bgNZuQsvcrlIfFB2NTu5 ZxBPszz7kyX1ZcJ9VsUWt38xk6LUnS3rFJhrf/K22G2xY3tXxGD3eliHEN+llx0+O7 UggIDgTz80xe229OFvFzjakDql5A9xeMIAHXSdNEMgvN0B6lqdT7ZY6UNVVM9SZGF6 3hrdTFkwl5hJGhnqC2R5Z/24WnQ+jReung9rjSaQUyiUS5qvEsYerpfNT24zgRl3TA 8lsPk90fDG0YQ== Date: Mon, 30 Sep 2024 13:20:32 +0200 From: Danilo Krummrich To: Yonatan Maman Cc: nouveau@lists.freedesktop.org, Gal Shalom Subject: Re: [PATCH 2/2] nouveau/dmem: Fix memory leak in `migrate_to_ram` upon copy error Message-ID: References: <20240923135449.356244-1-Ymaman@Nvidia.com> <20240923135449.356244-3-Ymaman@Nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240923135449.356244-3-Ymaman@Nvidia.com> X-BeenThere: nouveau@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Nouveau development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: nouveau-bounces@lists.freedesktop.org Sender: "Nouveau" On Mon, Sep 23, 2024 at 01:54:58PM +0000, Yonatan Maman wrote: > A copy push command might fail, causing `migrate_to_ram` to return a > dirty HIGH_USER page to the user. > > This exposes a security vulnerability in the nouveau driver. To prevent > memory leaks in `migrate_to_ram` upon a copy error, allocate a zero > page for the destination page. So, you refer to the case where this function fails in nouveau_dmem_copy_one()? If so, can you please explain why adding __GFP_ZERO to alloc_page_vma() helps with that? > > Signed-off-by: Yonatan Maman > Signed-off-by: Gal Shalom Since this is a bug, please also add a 'Fixes' tag, CC stable and add a 'Co-developed-by' tag if appropriate. > --- > drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c > index 6fb65b01d778..097bd3af0719 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c > +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c > @@ -193,7 +193,7 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf) > if (!spage || !(src & MIGRATE_PFN_MIGRATE)) > goto done; > > - dpage = alloc_page_vma(GFP_HIGHUSER, vmf->vma, vmf->address); > + dpage = alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vmf->vma, vmf->address); > if (!dpage) > goto done; > > -- > 2.34.1 >