From patchwork Tue Sep 1 15:10:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 264426 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, 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 94F89C433E6 for ; Tue, 1 Sep 2020 17:21:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68A082087D for ; Tue, 1 Sep 2020 17:21:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598980869; bh=KybOFCGDCwkwB7EpUhZBAkzFqWSShOO3eQjb3Z65DE4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uY+4x0FGqAqGb/p47qMOOsFwSH1d63ljDNhHAnevyCOYuiLLxmzdYPZNRnLAXzqRL cQcBQbg768fFWLVeQUTZv8YjUj07ddOZxou3KzpgrDCI8Fk1VLUycdGhWovmqaLBKo M6DOfVrDSECIhKXQxvw/L73f6NVZaYhuyY0HXzGY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730139AbgIARVG (ORCPT ); Tue, 1 Sep 2020 13:21:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:55224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728184AbgIAPMm (ORCPT ); Tue, 1 Sep 2020 11:12:42 -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 EA2B7208CA; Tue, 1 Sep 2020 15:12:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598973160; bh=KybOFCGDCwkwB7EpUhZBAkzFqWSShOO3eQjb3Z65DE4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LqV1AqjgWfaGj9fKb91W62BaZN24vH9EvCUFGpry19BD0nqwIrRcj8sGObq/z3tG0 U5oT3B10CWIKCL/OOBBcLxly5dykh7AHUbuv0SRUjm4ZsurQ+5Wir5wch2NZXwLbiF R1hufTnYGj0QPCPPWKStTHDM/KXv2tm8CgWEeKIQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Changming Liu , Sasha Levin Subject: [PATCH 4.4 31/62] USB: sisusbvga: Fix a potential UB casued by left shifting a negative value Date: Tue, 1 Sep 2020 17:10:14 +0200 Message-Id: <20200901150922.285365865@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901150920.697676718@linuxfoundation.org> References: <20200901150920.697676718@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 22da70fada5e5..971f1165dc4bb 100644 --- a/drivers/usb/misc/sisusbvga/sisusb.c +++ b/drivers/usb/misc/sisusbvga/sisusb.c @@ -790,7 +790,7 @@ 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