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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0CD34C433E1 for ; Mon, 17 Aug 2020 16:43:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE49E20657 for ; Mon, 17 Aug 2020 16:43:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597682594; bh=tEM0h2Eeq0xk2+/KRcSElEjI+YzKG8o5jvvzr5kp4tU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XR++46tcFtkjdLRLDZTq4H0EPy6CZ9U9KAcE99ugJ9qQjH9GCXMa1R48LzmqQ3+Gh 5hbBGEBfE4q3oBBsYkrSzBBWjP7qLvdBHdo7PBd84YOuUFf1oiFfvgiZoPaBJJQr9V YX7uqAmCSVI4zHAVWmaysTEvMGXclzpFyQWamRa8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388682AbgHQQnG (ORCPT ); Mon, 17 Aug 2020 12:43:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:46184 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730939AbgHQP6z (ORCPT ); Mon, 17 Aug 2020 11:58:55 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7936920760; Mon, 17 Aug 2020 15:58:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597679935; bh=tEM0h2Eeq0xk2+/KRcSElEjI+YzKG8o5jvvzr5kp4tU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0+TqDItDoGl0+80yDxxpfMRz9BfwWKA2ryTjo+1yPk8A89OLcp9DLcz7sZsZXkX7g Wii3N1I23AU6BSOmkujB2f3V5MXuCx8x0d4N3Av1uaLzIx1ETnkSfc0xikKf5WeUzJ vuGjlNiRJW3sIEgAb1HCFb6oPng/T/w6jcewsW64= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleksandr Andrushchenko , Juergen Gross Subject: [PATCH 5.7 383/393] xen/gntdev: Fix dmabuf import with non-zero sgt offset Date: Mon, 17 Aug 2020 17:17:13 +0200 Message-Id: <20200817143838.185481005@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143819.579311991@linuxfoundation.org> References: <20200817143819.579311991@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleksandr Andrushchenko commit 5fa4e6f1c2d8c9a4e47e1931b42893172d388f2b upstream. It is possible that the scatter-gather table during dmabuf import has non-zero offset of the data, but user-space doesn't expect that. Fix this by failing the import, so user-space doesn't access wrong data. Fixes: bf8dc55b1358 ("xen/gntdev: Implement dma-buf import functionality") Signed-off-by: Oleksandr Andrushchenko Acked-by: Juergen Gross Cc: Link: https://lore.kernel.org/r/20200813062113.11030-2-andr2000@gmail.com Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- drivers/xen/gntdev-dmabuf.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/xen/gntdev-dmabuf.c +++ b/drivers/xen/gntdev-dmabuf.c @@ -613,6 +613,14 @@ dmabuf_imp_to_refs(struct gntdev_dmabuf_ goto fail_detach; } + /* Check that we have zero offset. */ + if (sgt->sgl->offset) { + ret = ERR_PTR(-EINVAL); + pr_debug("DMA buffer has %d bytes offset, user-space expects 0\n", + sgt->sgl->offset); + goto fail_unmap; + } + /* Check number of pages that imported buffer has. */ if (attach->dmabuf->size != gntdev_dmabuf->nr_pages << PAGE_SHIFT) { ret = ERR_PTR(-EINVAL);