From f526afcd8f71945c23ce581d7864ace93de8a4f7 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 24 Apr 2018 08:04:41 +0200 Subject: ALSA: rme9652: Hardening for potential Spectre v1 As recently Smatch suggested, one place in RME9652 driver may expand the array directly from the user-space value with speculation: sound/pci/rme9652/rme9652.c:2074 snd_rme9652_channel_info() warn: potential spectre issue 'rme9652->channel_map' (local cap) This patch puts array_index_nospec() for hardening against it. BugLink: https://marc.info/?l=linux-kernel&m=152411496503418&w=2 Reported-by: Dan Carpenter Cc: Signed-off-by: Takashi Iwai --- sound/pci/rme9652/rme9652.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'sound/pci') diff --git a/sound/pci/rme9652/rme9652.c b/sound/pci/rme9652/rme9652.c index df648b1d9217..edd765e22377 100644 --- a/sound/pci/rme9652/rme9652.c +++ b/sound/pci/rme9652/rme9652.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -2071,9 +2072,10 @@ static int snd_rme9652_channel_info(struct snd_pcm_substream *substream, if (snd_BUG_ON(info->channel >= RME9652_NCHANNELS)) return -EINVAL; - if ((chn = rme9652->channel_map[info->channel]) < 0) { + chn = rme9652->channel_map[array_index_nospec(info->channel, + RME9652_NCHANNELS)]; + if (chn < 0) return -EINVAL; - } info->offset = chn * RME9652_CHANNEL_BUFFER_BYTES; info->first = 0; -- cgit v1.2.3-58-ga151