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 C0B42C433F5 for ; Tue, 18 Jan 2022 03:36:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354232AbiARDgg (ORCPT ); Mon, 17 Jan 2022 22:36:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353450AbiARDdE (ORCPT ); Mon, 17 Jan 2022 22:33:04 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 74DBFC037003; Mon, 17 Jan 2022 19:08:55 -0800 (PST) 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 033B760B32; Tue, 18 Jan 2022 03:08:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9159DC36AE3; Tue, 18 Jan 2022 03:08:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642475334; bh=4jx1Bl4S5uQyeaT0H4TWgXfSBRxVssLycfkRR4kmCkU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vCgnDIvH4iWVbiCmVsIZ67R78D4ZdEuXJHeWZ0xpx1tdbkBKgp1XCZP+LHoA0eynd F6us8nTH5ef4nKJe9s+1KrjixsFlrIBrYo+85YCHXq9rTtmt0HJr9p4NQKLVSf1+4x u6tttKsHwhdF49+gqEHiFnwlcx48pfM754rKCgtdf9CH+EFGvv5IBwKtNrFUJuAHoD W9I9G34OQOH6GlKPbddGvs64qrS79ajeMSmQCO/VQz5HRuv4uGuVGguTcH8TllPjtn +z787P08qBbU0F3Puh3YVDKpX3jzoXU4kH2zZfC9ZNuHhoYADiXumL6c98GA4Fu0Wm oqq0I4CTckicQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mauro Carvalho Chehab , rkardell@mida.se, Sasha Levin , mchehab@kernel.org, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 11/29] media: m920x: don't use stack on USB reads Date: Mon, 17 Jan 2022 22:08:04 -0500 Message-Id: <20220118030822.1955469-11-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220118030822.1955469-1-sashal@kernel.org> References: <20220118030822.1955469-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mauro Carvalho Chehab [ Upstream commit a2ab06d7c4d6bfd0b545a768247a70463e977e27 ] Using stack-allocated pointers for USB message data don't work. This driver is almost OK with that, except for the I2C read logic. Fix it by using a temporary read buffer, just like on all other calls to m920x_read(). Link: https://lore.kernel.org/all/ccc99e48-de4f-045e-0fe4-61e3118e3f74@mida.se/ Reported-by: rkardell@mida.se Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb/m920x.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/dvb-usb/m920x.c b/drivers/media/usb/dvb-usb/m920x.c index eafc5c82467f4..5b806779e2106 100644 --- a/drivers/media/usb/dvb-usb/m920x.c +++ b/drivers/media/usb/dvb-usb/m920x.c @@ -284,6 +284,13 @@ static int m920x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int nu /* Should check for ack here, if we knew how. */ } if (msg[i].flags & I2C_M_RD) { + char *read = kmalloc(1, GFP_KERNEL); + if (!read) { + ret = -ENOMEM; + kfree(read); + goto unlock; + } + for (j = 0; j < msg[i].len; j++) { /* Last byte of transaction? * Send STOP, otherwise send ACK. */ @@ -291,9 +298,12 @@ static int m920x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int nu if ((ret = m920x_read(d->udev, M9206_I2C, 0x0, 0x20 | stop, - &msg[i].buf[j], 1)) != 0) + read, 1)) != 0) goto unlock; + msg[i].buf[j] = read[0]; } + + kfree(read); } else { for (j = 0; j < msg[i].len; j++) { /* Last byte of transaction? Then send STOP. */ -- 2.34.1