From nobody Wed Dec 17 09:12:16 2025 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 EEE52C32772 for ; Tue, 23 Aug 2022 11:03:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356647AbiHWLDb (ORCPT ); Tue, 23 Aug 2022 07:03:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357388AbiHWLCO (ORCPT ); Tue, 23 Aug 2022 07:02:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE76C66A65; Tue, 23 Aug 2022 02:14:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6EFF660F54; Tue, 23 Aug 2022 09:14:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47165C433C1; Tue, 23 Aug 2022 09:14:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661246081; bh=/oMobxsHDcQ6CFIW6sFoMoFbRFb9fNLZWxhjzCQjgwg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xoUs7O1Ih6W1Q7hFRVHjDB3cwKDSzxWtMQGaJOpSeU8Oik5RkiriUBBGt2y9Cjhg/ vJdzI2mbcVFgGuVB89qU6HjSpG1ubXtrR+NVeqXd3zLtV/9YG9k1fWBdPEAsLY7aI7 93YI+q5Awk4/wzewajwa3G7+iyD6XD/ljmYJB9GI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nimish Mishra , Anirban Chakraborty , Debdeep Mukhopadhyay , Jerome Forissier , Jens Wiklander , Linus Torvalds Subject: [PATCH 4.19 284/287] tee: add overflow check in register_shm_helper() Date: Tue, 23 Aug 2022 10:27:33 +0200 Message-Id: <20220823080111.068435965@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080100.268827165@linuxfoundation.org> References: <20220823080100.268827165@linuxfoundation.org> User-Agent: quilt/0.67 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" From: Jens Wiklander commit 573ae4f13f630d6660008f1974c0a8a29c30e18a upstream. With special lengths supplied by user space, register_shm_helper() has an integer overflow when calculating the number of pages covered by a supplied user space memory region. This causes internal_get_user_pages_fast() a helper function of pin_user_pages_fast() to do a NULL pointer dereference: Unable to handle kernel NULL pointer dereference at virtual address 00000= 00000000010 Modules linked in: CPU: 1 PID: 173 Comm: optee_example_a Not tainted 5.19.0 #11 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pc : internal_get_user_pages_fast+0x474/0xa80 Call trace: internal_get_user_pages_fast+0x474/0xa80 pin_user_pages_fast+0x24/0x4c register_shm_helper+0x194/0x330 tee_shm_register_user_buf+0x78/0x120 tee_ioctl+0xd0/0x11a0 __arm64_sys_ioctl+0xa8/0xec invoke_syscall+0x48/0x114 Fix this by adding an an explicit call to access_ok() in tee_shm_register_user_buf() to catch an invalid user space address early. Fixes: 033ddf12bcf5 ("tee: add register user memory") Cc: stable@vger.kernel.org Reported-by: Nimish Mishra Reported-by: Anirban Chakraborty Reported-by: Debdeep Mukhopadhyay Suggested-by: Jerome Forissier Signed-off-by: Jens Wiklander Signed-off-by: Linus Torvalds [JW: backport to stable-4.19 + update commit message] Signed-off-by: Jens Wiklander Signed-off-by: Greg Kroah-Hartman --- drivers/tee/tee_core.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -175,6 +175,10 @@ tee_ioctl_shm_register(struct tee_contex if (data.flags) return -EINVAL; =20 + if (!access_ok(VERIFY_WRITE, (void __user *)(unsigned long)data.addr, + data.length)) + return -EFAULT; + shm =3D tee_shm_register(ctx, data.addr, data.length, TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED); if (IS_ERR(shm))