From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4FE7DC433E6 for ; Tue, 1 Sep 2020 16:24:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 224C9206FA for ; Tue, 1 Sep 2020 16:24:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598977468; bh=gwf4wWC0vORa2uGQfb3OiUSJDKLfwwSQvhew2ikLsvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TONPfigdUwKcA8WkNuKoH2mGuudEBXMX5WigXl9oAegKOa6r1SUzCkIYpqs0FFP2v cDkfsr2nepsQnjlzNBkTEEyZnkSgd4hDBjRxn4axjXiRBQ7/RvJESJuN6I4DaBG0jD jNv4R2w0FCiyeXWfBlsvUC+a1UcOOAIXCtJVcFaA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730927AbgIAPcO (ORCPT ); Tue, 1 Sep 2020 11:32:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:60638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730588AbgIAPa0 (ORCPT ); Tue, 1 Sep 2020 11:30:26 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B15B2206C0; Tue, 1 Sep 2020 15:30:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598974225; bh=gwf4wWC0vORa2uGQfb3OiUSJDKLfwwSQvhew2ikLsvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nqGQpLPdLRCATD8XbKESYA4F1z/NC/p/9xoYL+fAhh68a0xKbB/F8Y13eXcDBtLxq 9GfjIu/ZyBmdGBKcpn5GhqvStkxUDO+xaTkWDbKQ4O+ifvZGiG/dmXTWPur82lVd6f tYTzdqjcpLhNia8WUQCX1AQ4rcVdnVz8VtHjsWgU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Changming Liu , Sasha Levin Subject: [PATCH 5.4 063/214] USB: sisusbvga: Fix a potential UB casued by left shifting a negative value Date: Tue, 1 Sep 2020 17:09:03 +0200 Message-Id: <20200901150955.997013862@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901150952.963606936@linuxfoundation.org> References: <20200901150952.963606936@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Changming Liu [ Upstream commit 2b53a19284f537168fb506f2f40d7fda40a01162 ] The char buffer buf, receives data directly from user space, so its content might be negative and its elements are left shifted to form an unsigned integer. Since left shifting a negative value is undefined behavior, thus change the char to u8 to elimintate this UB. Signed-off-by: Changming Liu Link: https://lore.kernel.org/r/20200711043018.928-1-charley.ashbringer@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/misc/sisusbvga/sisusb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/misc/sisusbvga/sisusb.c b/drivers/usb/misc/sisusbvga/sisusb.c index fc8a5da4a07c9..0734e6dd93862 100644 --- a/drivers/usb/misc/sisusbvga/sisusb.c +++ b/drivers/usb/misc/sisusbvga/sisusb.c @@ -761,7 +761,7 @@ static int sisusb_write_mem_bulk(struct sisusb_usb_data *sisusb, u32 addr, u8 swap8, fromkern = kernbuffer ? 1 : 0; u16 swap16; u32 swap32, flag = (length >> 28) & 1; - char buf[4]; + u8 buf[4]; /* if neither kernbuffer not userbuffer are given, assume * data in obuf -- 2.25.1