From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59806 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388556AbeIXSrg (ORCPT ); Mon, 24 Sep 2018 14:47:36 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Tomas Winkler Subject: [PATCH 4.18 234/235] mei: bus: type promotion bug in mei_nfc_if_version() Date: Mon, 24 Sep 2018 13:53:40 +0200 Message-Id: <20180924113126.113229959@linuxfoundation.org> In-Reply-To: <20180924113103.999624566@linuxfoundation.org> References: <20180924113103.999624566@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit b40b3e9358fbafff6a4ba0f4b9658f6617146f9c upstream. We accidentally removed the check for negative returns without considering the issue of type promotion. The "if_version_length" variable is type size_t so if __mei_cl_recv() returns a negative then "bytes_recv" is type promoted to a high positive value and treated as success. Cc: Fixes: 582ab27a063a ("mei: bus: fix received data size check in NFC fixup") Signed-off-by: Dan Carpenter Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/bus-fixup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/misc/mei/bus-fixup.c +++ b/drivers/misc/mei/bus-fixup.c @@ -267,7 +267,7 @@ static int mei_nfc_if_version(struct mei ret = 0; bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length, 0); - if (bytes_recv < if_version_length) { + if (bytes_recv < 0 || bytes_recv < if_version_length) { dev_err(bus->dev, "Could not read IF version\n"); ret = -EIO; goto err;