From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033526AbdEWUfw (ORCPT ); Tue, 23 May 2017 16:35:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49930 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033481AbdEWUfl (ORCPT ); Tue, 23 May 2017 16:35:41 -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 4.4 008/103] tpm_crb: check for bad response size Date: Tue, 23 May 2017 22:08:34 +0200 Message-Id: <20170523200857.855439187@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170523200856.903752266@linuxfoundation.org> References: <20170523200856.903752266@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-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 @@ -118,8 +118,7 @@ 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);