From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49010 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726384AbeICV7y (ORCPT ); Mon, 3 Sep 2018 17:59:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ricardo Schwarzmeier , Jarkko Sakkinen Subject: [PATCH 4.18 104/123] tpm: Return the actual size when receiving an unsupported command Date: Mon, 3 Sep 2018 18:57:28 +0200 Message-Id: <20180903165723.925085589@linuxfoundation.org> In-Reply-To: <20180903165719.499675257@linuxfoundation.org> References: <20180903165719.499675257@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ricardo Schwarzmeier commit 36a11029b07ee30bdc4553274d0efea645ed9d91 upstream. The userpace expects to read the number of bytes stated in the header. Returning the size of the buffer instead would be unexpected. Cc: stable@vger.kernel.org Fixes: 095531f891e6 ("tpm: return a TPM_RC_COMMAND_CODE response if command is not implemented") Signed-off-by: Ricardo Schwarzmeier Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm-interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -423,7 +423,7 @@ static ssize_t tpm_try_transmit(struct t header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE | TSS2_RESMGR_TPM_RC_LAYER); - return bufsiz; + return sizeof(*header); } if (bufsiz > TPM_BUFSIZE)