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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 A3627C677D4 for ; Mon, 8 Oct 2018 18:53:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E91B204FD for ; Mon, 8 Oct 2018 18:53:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="19s5ocxe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E91B204FD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732661AbeJICGL (ORCPT ); Mon, 8 Oct 2018 22:06:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:56422 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728203AbeJICGK (ORCPT ); Mon, 8 Oct 2018 22:06:10 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (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 E0C40204FD; Mon, 8 Oct 2018 18:53:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539024782; bh=HvNPnnT2dAuAYxGz8YW7G+ZCsYshitUnFPyctHlr7QU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=19s5ocxeDvPAtv0KoMUzZ7lBt6Vl84PZf7/dM9RVi7G4FOEsGtrQ3XLmOxZqwmcQy s2Vj87TVccLo/0e2tL7jnBicbqfI6hn4g1/D2rVuqQKLrSimR2g6mYQ34cCBYL2Eed HCBvFhzFVn7wjXzx2FeZYlHWqo8IEssHrT20Z8Q0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vikram Mulukutla , Rishabh Bhatnagar , Luis Chamberlain Subject: [PATCH 4.18 152/168] firmware: Fix security issue with request_firmware_into_buf() Date: Mon, 8 Oct 2018 20:32:12 +0200 Message-Id: <20181008175625.821277657@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181008175620.043587728@linuxfoundation.org> References: <20181008175620.043587728@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rishabh Bhatnagar commit 422b3db2a5036add39a82425b1dd9fb6c96481e8 upstream. When calling request_firmware_into_buf() with the FW_OPT_NOCACHE flag it is expected that firmware is loaded into buffer from memory. But inside alloc_lookup_fw_priv every new firmware that is loaded is added to the firmware cache (fwc) list head. So if any driver requests a firmware that is already loaded the code iterates over the above mentioned list and it can end up giving a pointer to other device driver's firmware buffer. Also the existing copy may either be modified by drivers, remote processors or even freed. This causes a potential security issue with batched requests when using request_firmware_into_buf. Fix alloc_lookup_fw_priv to not add to the fwc head list if FW_OPT_NOCACHE is set, and also don't do the lookup in the list. Fixes: 0e742e9275 ("firmware: provide infrastructure to make fw caching optional") [mcgrof: broken since feature introduction on v4.8] Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Vikram Mulukutla Signed-off-by: Rishabh Bhatnagar Signed-off-by: Luis Chamberlain Signed-off-by: Greg Kroah-Hartman --- drivers/base/firmware_loader/main.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -209,21 +209,24 @@ static struct fw_priv *__lookup_fw_priv( static int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc, struct fw_priv **fw_priv, void *dbuf, - size_t size) + size_t size, enum fw_opt opt_flags) { struct fw_priv *tmp; spin_lock(&fwc->lock); - tmp = __lookup_fw_priv(fw_name); - if (tmp) { - kref_get(&tmp->ref); - spin_unlock(&fwc->lock); - *fw_priv = tmp; - pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n"); - return 1; + if (!(opt_flags & FW_OPT_NOCACHE)) { + tmp = __lookup_fw_priv(fw_name); + if (tmp) { + kref_get(&tmp->ref); + spin_unlock(&fwc->lock); + *fw_priv = tmp; + pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n"); + return 1; + } } + tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size); - if (tmp) + if (tmp && !(opt_flags & FW_OPT_NOCACHE)) list_add(&tmp->list, &fwc->head); spin_unlock(&fwc->lock); @@ -493,7 +496,8 @@ int assign_fw(struct firmware *fw, struc */ static int _request_firmware_prepare(struct firmware **firmware_p, const char *name, - struct device *device, void *dbuf, size_t size) + struct device *device, void *dbuf, size_t size, + enum fw_opt opt_flags) { struct firmware *firmware; struct fw_priv *fw_priv; @@ -511,7 +515,8 @@ _request_firmware_prepare(struct firmwar return 0; /* assigned */ } - ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size); + ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size, + opt_flags); /* * bind with 'priv' now to avoid warning in failure path @@ -571,7 +576,8 @@ _request_firmware(const struct firmware goto out; } - ret = _request_firmware_prepare(&fw, name, device, buf, size); + ret = _request_firmware_prepare(&fw, name, device, buf, size, + opt_flags); if (ret <= 0) /* error or already assigned */ goto out;