As the recent Smatch warned, 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 dan.carpenter@oracle.com Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/pci/rme9652/rme9652.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
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 <linux/pci.h> #include <linux/module.h> #include <linux/io.h> +#include <linux/nospec.h>
#include <sound/core.h> #include <sound/control.h> @@ -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;