Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39050 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754624AbeCWKEI (ORCPT ); Fri, 23 Mar 2018 06:04:08 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeremy Boone , James Bottomley , Jarkko Sakkinen , James Morris Subject: [PATCH 4.9 001/177] tpm: fix potential buffer overruns caused by bit glitches on the bus Date: Fri, 23 Mar 2018 10:52:09 +0100 Message-Id: <20180323094205.172538837@linuxfoundation.org> In-Reply-To: <20180323094205.090519271@linuxfoundation.org> References: <20180323094205.090519271@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable 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 Cc: stable@vger.kernel.org Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm-interface.c | 5 +++++ drivers/char/tpm/tpm2-cmd.c | 6 ++++++ 2 files changed, 11 insertions(+) --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1078,6 +1078,11 @@ 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; --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -668,6 +668,11 @@ static int tpm2_unseal_cmd(struct tpm_ch if (!rc) { data_len = be16_to_cpup( (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]); + if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) { + rc = -EFAULT; + goto out; + } + data = &buf.data[TPM_HEADER_SIZE + 6]; memcpy(payload->key, data, data_len - 1); @@ -675,6 +680,7 @@ static int tpm2_unseal_cmd(struct tpm_ch payload->migratable = data[data_len - 1]; } +out: tpm_buf_destroy(&buf); return rc; }