From 10513142a7114d251670361ad40cba2c61403406 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 24 Apr 2018 08:03:14 +0200 Subject: 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: Dan Carpenter Cc: Signed-off-by: Takashi Iwai --- sound/pci/rme9652/hdspm.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) (limited to 'sound/pci') diff --git a/sound/pci/rme9652/hdspm.c b/sound/pci/rme9652/hdspm.c index 4c59983158e0..11b5b5e0e058 100644 --- 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 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; } -- cgit v1.2.3