Commit 10513142 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: hdspm: Hardening for potential Spectre v1 

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: default avatarDan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent f9d94b57

sound/pci/rme9652/hdspm.c

+14 −10
Original line number Diff line number Diff line
@@ -137,6 +137,7 @@ 
#include <linux/pci.h>

#include <linux/math64.h>

#include <linux/io.h>

#include <linux/nospec.h>



#include <sound/core.h>

#include <sound/control.h>
@@ -5698,40 +5699,43 @@ static int snd_hdspm_channel_info(struct snd_pcm_substream *substream, 
		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;

	}

CRA Git | Maintained and supported by SUSTech CRA and CCSE