From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: [PATCH 8/8] ALSA: rme9652: Hardening for potential Spectre v1 Date: Tue, 24 Apr 2018 09:56:19 +0200 Message-ID: <20180424075619.29602-9-tiwai@suse.de> References: <20180424075619.29602-1-tiwai@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id E3FB7267688 for ; Tue, 24 Apr 2018 09:56:42 +0200 (CEST) In-Reply-To: <20180424075619.29602-1-tiwai@suse.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org Cc: Dan Carpenter List-Id: alsa-devel@alsa-project.org 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 Signed-off-by: Takashi Iwai --- 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 #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; -- 2.16.3