| From f526afcd8f71945c23ce581d7864ace93de8a4f7 Mon Sep 17 00:00:00 2001 |
| From: Takashi Iwai <tiwai@suse.de> |
| Date: Tue, 24 Apr 2018 08:04:41 +0200 |
| Subject: ALSA: rme9652: Hardening for potential Spectre v1 |
| |
| From: Takashi Iwai <tiwai@suse.de> |
| |
| commit f526afcd8f71945c23ce581d7864ace93de8a4f7 upstream. |
| |
| 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 <dan.carpenter@oracle.com> |
| Cc: <stable@vger.kernel.org> |
| Signed-off-by: Takashi Iwai <tiwai@suse.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| sound/pci/rme9652/rme9652.c | 6 ++++-- |
| 1 file changed, 4 insertions(+), 2 deletions(-) |
| |
| --- 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> |
| @@ -2036,9 +2037,10 @@ static int snd_rme9652_channel_info(stru |
| 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; |
