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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40729C433FE for ; Mon, 24 Jan 2022 18:59:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344729AbiAXS7A (ORCPT ); Mon, 24 Jan 2022 13:59:00 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:55858 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245730AbiAXS4o (ORCPT ); Mon, 24 Jan 2022 13:56:44 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 90D1E61540; Mon, 24 Jan 2022 18:56:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64C68C340E5; Mon, 24 Jan 2022 18:56:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643050603; bh=xyb7el4B8LdNx+P5MYu2OzNDCK3CD8EPUq/+flDETEc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uPNDvbVym2SsJEB4PnUG5+epDqOj/36wOvaKKU2Tc38ixgQ7CmMuwtQ5Cwv0o3uhZ h6CgBRgm5V3svGnz9VHTQiDN2a03BGr1gWcgVDGplEyYFrWj9rcA+ZuTl8P28RljBy LS5BO+efNLxRYgTHqFIf3Ho7kEt1zktYMjHNozsY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Skripkin , Arnd Bergmann , Jakub Kicinski , Sasha Levin , syzbot+003c0a286b9af5412510@syzkaller.appspotmail.com Subject: [PATCH 4.9 055/157] net: mcs7830: handle usb read errors properly Date: Mon, 24 Jan 2022 19:42:25 +0100 Message-Id: <20220124183934.529532759@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183932.787526760@linuxfoundation.org> References: <20220124183932.787526760@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Skripkin [ Upstream commit d668769eb9c52b150753f1653f7f5a0aeb8239d2 ] Syzbot reported uninit value in mcs7830_bind(). The problem was in missing validation check for bytes read via usbnet_read_cmd(). usbnet_read_cmd() internally calls usb_control_msg(), that returns number of bytes read. Code should validate that requested number of bytes was actually read. So, this patch adds missing size validation check inside mcs7830_get_reg() to prevent uninit value bugs Reported-and-tested-by: syzbot+003c0a286b9af5412510@syzkaller.appspotmail.com Fixes: 2a36d7083438 ("USB: driver for mcs7830 (aka DeLOCK) USB ethernet adapter") Signed-off-by: Pavel Skripkin Reviewed-by: Arnd Bergmann Link: https://lore.kernel.org/r/20220106225716.7425-1-paskripkin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/usb/mcs7830.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/net/usb/mcs7830.c b/drivers/net/usb/mcs7830.c index 4f345bd4e6e29..95151b46f2001 100644 --- a/drivers/net/usb/mcs7830.c +++ b/drivers/net/usb/mcs7830.c @@ -121,8 +121,16 @@ static const char driver_name[] = "MOSCHIP usb-ethernet driver"; static int mcs7830_get_reg(struct usbnet *dev, u16 index, u16 size, void *data) { - return usbnet_read_cmd(dev, MCS7830_RD_BREQ, MCS7830_RD_BMREQ, - 0x0000, index, data, size); + int ret; + + ret = usbnet_read_cmd(dev, MCS7830_RD_BREQ, MCS7830_RD_BMREQ, + 0x0000, index, data, size); + if (ret < 0) + return ret; + else if (ret < size) + return -ENODATA; + + return ret; } static int mcs7830_set_reg(struct usbnet *dev, u16 index, u16 size, const void *data) -- 2.34.1