3.16.60-rc1 review patch. If anyone has any objections, please let me know.
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From: Takashi Iwai tiwai@suse.de
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 dan.carpenter@oracle.com Signed-off-by: Takashi Iwai tiwai@suse.de [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- 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 <linux/pci.h> #include <linux/math64.h> #include <asm/io.h> +#include <linux/nospec.h>
#include <sound/core.h> #include <sound/control.h> @@ -5724,40 +5725,43 @@ 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; }