From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id zO9rCak+GVtNSwAAmS7hNA ; Thu, 07 Jun 2018 14:18:38 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 0E14A6089E; Thu, 7 Jun 2018 14:18:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id 516BC6063F; Thu, 7 Jun 2018 14:18:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 516BC6063F Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933178AbeFGORu (ORCPT + 25 others); Thu, 7 Jun 2018 10:17:50 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39551 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933099AbeFGOJN (ORCPT ); Thu, 7 Jun 2018 10:09:13 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvbD-0005Zq-Cw; Thu, 07 Jun 2018 15:09:11 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvbA-00039W-AL; Thu, 07 Jun 2018 15:09:08 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "James Morris" , "James Bottomley" , "Jeremy Boone" , "Jarkko Sakkinen" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 298/410] tpm: fix potential buffer overruns caused by bit glitches on the bus In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Boone commit 3be23274755ee85771270a23af7691dc9b3a95db upstream. Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. If a bit does flip it could cause an overrun if it's in one of the size parameters, so sanity check that we're not overrunning the provided buffer when doing a memcpy(). Signed-off-by: Jeremy Boone Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: James Morris [bwh: Backported to 3.16: Drop the TPM2 bits] Signed-off-by: Ben Hutchings --- drivers/char/tpm/tpm-interface.c | 4 ++++ drivers/char/tpm/tpm2-cmd.c | 4 ++++ 2 files changed, 8 insertions(+) --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1029,6 +1029,10 @@ int tpm_get_random(u32 chip_num, u8 *out break; recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len); + if (recd > num_bytes) { + total = -EFAULT; + break; + } memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd); dest += recd;