From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:36508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756354AbeD3T2g (ORCPT ); Mon, 30 Apr 2018 15:28:36 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Takashi Iwai Subject: [PATCH 4.16 043/113] ALSA: hdspm: Hardening for potential Spectre v1 Date: Mon, 30 Apr 2018 12:24:14 -0700 Message-Id: <20180430184016.875135579@linuxfoundation.org> In-Reply-To: <20180430184015.043892819@linuxfoundation.org> References: <20180430184015.043892819@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai commit 10513142a7114d251670361ad40cba2c61403406 upstream. As recently Smatch suggested, a couple of places in HDSP MADI driver may expand the array directly from the user-space value with speculation: sound/pci/rme9652/hdspm.c:5717 snd_hdspm_channel_info() warn: potential spectre issue 'hdspm->channel_map_out' (local cap) sound/pci/rme9652/hdspm.c:5734 snd_hdspm_channel_info() warn: potential spectre issue 'hdspm->channel_map_in' (local cap) This patch puts array_index_nospec() for hardening against them. BugLink: https://marc.info/?l=linux-kernel&m=152411496503418&w=2 Reported-by: Dan Carpenter Cc: Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/pci/rme9652/hdspm.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) --- a/sound/pci/rme9652/hdspm.c +++ b/sound/pci/rme9652/hdspm.c @@ -137,6 +137,7 @@ #include #include #include +#include #include #include @@ -5698,40 +5699,43 @@ static int snd_hdspm_channel_info(struct struct snd_pcm_channel_info *info) { struct hdspm *hdspm = snd_pcm_substream_chip(substream); + unsigned int channel = info->channel; if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { - if (snd_BUG_ON(info->channel >= hdspm->max_channels_out)) { + if (snd_BUG_ON(channel >= hdspm->max_channels_out)) { dev_info(hdspm->card->dev, "snd_hdspm_channel_info: output channel out of range (%d)\n", - info->channel); + channel); return -EINVAL; } - if (hdspm->channel_map_out[info->channel] < 0) { + channel = array_index_nospec(channel, hdspm->max_channels_out); + if (hdspm->channel_map_out[channel] < 0) { dev_info(hdspm->card->dev, "snd_hdspm_channel_info: output channel %d mapped out\n", - info->channel); + channel); return -EINVAL; } - info->offset = hdspm->channel_map_out[info->channel] * + info->offset = hdspm->channel_map_out[channel] * HDSPM_CHANNEL_BUFFER_BYTES; } else { - if (snd_BUG_ON(info->channel >= hdspm->max_channels_in)) { + if (snd_BUG_ON(channel >= hdspm->max_channels_in)) { dev_info(hdspm->card->dev, "snd_hdspm_channel_info: input channel out of range (%d)\n", - info->channel); + channel); return -EINVAL; } - if (hdspm->channel_map_in[info->channel] < 0) { + channel = array_index_nospec(channel, hdspm->max_channels_in); + if (hdspm->channel_map_in[channel] < 0) { dev_info(hdspm->card->dev, "snd_hdspm_channel_info: input channel %d mapped out\n", - info->channel); + channel); return -EINVAL; } - info->offset = hdspm->channel_map_in[info->channel] * + info->offset = hdspm->channel_map_in[channel] * HDSPM_CHANNEL_BUFFER_BYTES; }