From patchwork Mon Jun 14 22:33:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tyler Hicks X-Patchwork-Id: 12320151 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=-26.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 882CDC49EA3 for ; Mon, 14 Jun 2021 22:33:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 728C3613B9 for ; Mon, 14 Jun 2021 22:33:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231667AbhFNWfq (ORCPT ); Mon, 14 Jun 2021 18:35:46 -0400 Received: from linux.microsoft.com ([13.77.154.182]:56108 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231674AbhFNWfl (ORCPT ); Mon, 14 Jun 2021 18:35:41 -0400 Received: from sequoia.work.tihix.com (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id 422CE20B83CB; Mon, 14 Jun 2021 15:33:37 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 422CE20B83CB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1623710018; bh=ovzjhUAHZMUAXxwPnn8UpOWfyMHiT8Tau4YH/N0hSac=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jXE6leNzv4aWPewhbdj1JDdeG1hXyxsffs4eNPSWIu9paaelY2CjgKRxM0EPibOe4 uosh7V00cSO+hXQePLpS5wPajLoWBeQHvwBvzNIZcpHmZOi/t2tHQJ3H4GWdHeh66l 0osgJuKCu+0ORGhrVPiyVeejQ0iwKnluYbvSGRp4= From: Tyler Hicks To: Jens Wiklander , Allen Pais , Sumit Garg , Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , Vikas Gupta Cc: Thirupathaiah Annapureddy , Pavel Tatashin , =?utf-8?b?UmFmYcWCIE1pxYJlY2tp?= , op-tee@lists.trustedfirmware.org, linux-integrity@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 4/8] optee: Clear stale cache entries during initialization Date: Mon, 14 Jun 2021 17:33:13 -0500 Message-Id: <20210614223317.999867-5-tyhicks@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210614223317.999867-1-tyhicks@linux.microsoft.com> References: <20210614223317.999867-1-tyhicks@linux.microsoft.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The shm cache could contain invalid addresses if optee_disable_shm_cache() was not called from the .shutdown hook of the previous kernel before a kexec. These addresses could be unmapped or they could point to mapped but unintended locations in memory. Clear the shared memory cache, while being careful to not translate the addresses returned from OPTEE_SMC_DISABLE_SHM_CACHE, during driver initialization. Once all pre-cache shm objects are removed, proceed with enabling the cache so that we know that we can handle cached shm objects with confidence later in the .shutdown hook. Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks Reviewed-by: Jens Wiklander --- drivers/tee/optee/call.c | 36 ++++++++++++++++++++++++++++--- drivers/tee/optee/core.c | 9 ++++++++ drivers/tee/optee/optee_private.h | 1 + 3 files changed, 43 insertions(+), 3 deletions(-) diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c index 6e6eb836e9b6..387e94768182 100644 --- a/drivers/tee/optee/call.c +++ b/drivers/tee/optee/call.c @@ -416,11 +416,13 @@ void optee_enable_shm_cache(struct optee *optee) } /** - * optee_disable_shm_cache() - Disables caching of some shared memory allocation - * in OP-TEE + * __optee_disable_shm_cache() - Disables caching of some shared memory + * allocation in OP-TEE * @optee: main service struct + * @is_mapped: true if the cached shared memory addresses were mapped by this + * kernel, are safe to dereference, and should be freed */ -void optee_disable_shm_cache(struct optee *optee) +static void __optee_disable_shm_cache(struct optee *optee, bool is_mapped) { struct optee_call_waiter w; @@ -439,6 +441,13 @@ void optee_disable_shm_cache(struct optee *optee) if (res.result.status == OPTEE_SMC_RETURN_OK) { struct tee_shm *shm; + /* + * Shared memory references that were not mapped by + * this kernel must be ignored to prevent a crash. + */ + if (!is_mapped) + continue; + shm = reg_pair_to_ptr(res.result.shm_upper32, res.result.shm_lower32); tee_shm_free(shm); @@ -449,6 +458,27 @@ void optee_disable_shm_cache(struct optee *optee) optee_cq_wait_final(&optee->call_queue, &w); } +/** + * optee_disable_shm_cache() - Disables caching of mapped shared memory + * allocations in OP-TEE + * @optee: main service struct + */ +void optee_disable_shm_cache(struct optee *optee) +{ + return __optee_disable_shm_cache(optee, true); +} + +/** + * optee_disable_unmapped_shm_cache() - Disables caching of shared memory + * allocations in OP-TEE which are not + * currently mapped + * @optee: main service struct + */ +void optee_disable_unmapped_shm_cache(struct optee *optee) +{ + return __optee_disable_shm_cache(optee, false); +} + #define PAGELIST_ENTRIES_PER_PAGE \ ((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1) diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 0987074d7ed0..651d49b53d3b 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -716,6 +716,15 @@ static int optee_probe(struct platform_device *pdev) optee->memremaped_shm = memremaped_shm; optee->pool = pool; + /* + * Ensure that there are no pre-existing shm objects before enabling + * the shm cache so that there's no chance of receiving an invalid + * address during shutdown. This could occur, for example, if we're + * kexec booting from an older kernel that did not properly cleanup the + * shm cache. + */ + optee_disable_unmapped_shm_cache(optee); + optee_enable_shm_cache(optee); if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM) diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index e25b216a14ef..dbdd367be156 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -159,6 +159,7 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session); void optee_enable_shm_cache(struct optee *optee); void optee_disable_shm_cache(struct optee *optee); +void optee_disable_unmapped_shm_cache(struct optee *optee); int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm, struct page **pages, size_t num_pages,