From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47652 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1032000AbdEWUYd (ORCPT ); Tue, 23 May 2017 16:24:33 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jerry Snitselaar , Jarkko Sakkinen Subject: [PATCH 4.9 018/164] tpm_crb: check for bad response size Date: Tue, 23 May 2017 22:07:15 +0200 Message-Id: <20170523200908.133292536@linuxfoundation.org> In-Reply-To: <20170523200907.297534241@linuxfoundation.org> References: <20170523200907.297534241@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: Jerry Snitselaar commit 8569defde8057258835c51ce01a33de82e14b148 upstream. Make sure size of response buffer is at least 6 bytes, or we will underflow and pass large size_t to memcpy_fromio(). This was encountered while testing earlier version of locality patchset. Fixes: 30fc8d138e912 ("tpm: TPM 2.0 CRB Interface") Signed-off-by: Jerry Snitselaar Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm_crb.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -111,8 +111,7 @@ static int crb_recv(struct tpm_chip *chi memcpy_fromio(buf, priv->rsp, 6); expected = be32_to_cpup((__be32 *) &buf[2]); - - if (expected > count) + if (expected > count || expected < 6) return -EIO; memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);