From nobody Fri Jan 2 01:46:52 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C81CCDB474 for ; Tue, 17 Oct 2023 20:26:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344484AbjJQU0H (ORCPT ); Tue, 17 Oct 2023 16:26:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344496AbjJQUZo (ORCPT ); Tue, 17 Oct 2023 16:25:44 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 273F8118; Tue, 17 Oct 2023 13:25:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697574339; x=1729110339; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=acK3P8RbFbLJ3Y/qsHvg8A7W0ea+PDycu9fLk45ERVg=; b=bAwYhPFDDn2o4/g5Fs2i2s5um2j26EQWQIyBaZJ2aaH4c46DESSmKzjG m8qgnDnrDqfr9zfj/plTmMMnQ9zukuTursZT/jQ40fKZMUrMtz/at8UjB 2l4v9tWYfqrSphZ+M3Cau2AbRLqI7cmk5duZAgPeY3kh5iehrPes69QO8 jBjP+2X9WgAAlW4iqXjd8rIbUUlrF8lLVOJR7htbOzfKiGP3cWF0qEI1e 21/snBiup9feaslOPp3z2p9HInLQpMahJKFB49EzoOfCu4atkY9+5wd+O Yaa8lCqGFJg1pF8Gipjp5bndl2kLgoWjnStIFm212TwtidEDXcPnrKg6U w==; X-IronPort-AV: E=McAfee;i="6600,9927,10866"; a="7429610" X-IronPort-AV: E=Sophos;i="6.03,233,1694761200"; d="scan'208";a="7429610" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Oct 2023 13:25:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10866"; a="900040478" X-IronPort-AV: E=Sophos;i="6.03,233,1694761200"; d="scan'208";a="900040478" Received: from rtdinh-mobl1.amr.corp.intel.com (HELO rpedgeco-desk4.intel.com) ([10.212.150.155]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Oct 2023 13:23:35 -0700 From: Rick Edgecombe To: x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, luto@kernel.org, peterz@infradead.org, kirill.shutemov@linux.intel.com, elena.reshetova@intel.com, isaku.yamahata@intel.com, seanjc@google.com, Michael Kelley , thomas.lendacky@amd.com, decui@microsoft.com, sathyanarayanan.kuppuswamy@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Cc: rick.p.edgecombe@intel.com, "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , linux-hyperv@vger.kernel.org Subject: [RFC 10/10] uio_hv_generic: Don't free decrypted memory Date: Tue, 17 Oct 2023 13:25:05 -0700 Message-Id: <20231017202505.340906-11-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231017202505.340906-1-rick.p.edgecombe@intel.com> References: <20231017202505.340906-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" On TDX it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. uio_hv_generic could free decrypted/shared pages if set_memory_decrypted() fails. Check the decrypted field in the gpadl before freeing in order to not leak the memory. Only compile tested. Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Wei Liu Cc: Dexuan Cui Cc: linux-hyperv@vger.kernel.org Signed-off-by: Rick Edgecombe --- drivers/uio/uio_hv_generic.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c index 20d9762331bd..6be3462b109f 100644 --- a/drivers/uio/uio_hv_generic.c +++ b/drivers/uio/uio_hv_generic.c @@ -181,12 +181,14 @@ hv_uio_cleanup(struct hv_device *dev, struct hv_uio_p= rivate_data *pdata) { if (pdata->send_gpadl.gpadl_handle) { vmbus_teardown_gpadl(dev->channel, &pdata->send_gpadl); - vfree(pdata->send_buf); + if (!pdata->send_gpadl.decrypted) + vfree(pdata->send_buf); } =20 if (pdata->recv_gpadl.gpadl_handle) { vmbus_teardown_gpadl(dev->channel, &pdata->recv_gpadl); - vfree(pdata->recv_buf); + if (!pdata->recv_gpadl.decrypted) + vfree(pdata->recv_buf); } } =20 @@ -295,7 +297,8 @@ hv_uio_probe(struct hv_device *dev, ret =3D vmbus_establish_gpadl(channel, pdata->recv_buf, RECV_BUFFER_SIZE, &pdata->recv_gpadl); if (ret) { - vfree(pdata->recv_buf); + if (!pdata->recv_gpadl.decrypted) + vfree(pdata->recv_buf); goto fail_close; } =20 @@ -317,7 +320,8 @@ hv_uio_probe(struct hv_device *dev, ret =3D vmbus_establish_gpadl(channel, pdata->send_buf, SEND_BUFFER_SIZE, &pdata->send_gpadl); if (ret) { - vfree(pdata->send_buf); + if (!pdata->send_gpadl.decrypted) + vfree(pdata->send_buf); goto fail_close; } =20 --=20 2.34.1