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authorTakashi Iwai <tiwai@suse.de>2018-04-24 08:50:50 +0300
committerTakashi Iwai <tiwai@suse.de>2018-04-25 11:37:46 +0300
commit69fa6f19b95597618ab30438a27b67ad93daa7c7 (patch)
treef8955b74773bf46e93e0e8c8293d59800504e1b4 /sound/pci
parent088e861edffb84879cf0c0d1b02eda078c3a0ffe (diff)
downloadlinux-69fa6f19b95597618ab30438a27b67ad93daa7c7.tar.xz
ALSA: hda: Hardening for potential Spectre v1
As recently Smatch suggested, one place in HD-audio hwdep ioctl codes may expand the array directly from the user-space value with speculation: sound/pci/hda/hda_local.h:467 get_wcaps() warn: potential spectre issue 'codec->wcaps' As get_wcaps() itself is a fairly frequently called inline function, and there is only one single call with a user-space value, we replace only the latter one to open-code locally with array_index_nospec() hardening in this patch. 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>
Diffstat (limited to 'sound/pci')
-rw-r--r--sound/pci/hda/hda_hwdep.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/sound/pci/hda/hda_hwdep.c b/sound/pci/hda/hda_hwdep.c
index 57df06e76968..cc009a4a3d1d 100644
--- a/sound/pci/hda/hda_hwdep.c
+++ b/sound/pci/hda/hda_hwdep.c
@@ -21,6 +21,7 @@
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/compat.h>
+#include <linux/nospec.h>
#include <sound/core.h>
#include "hda_codec.h"
#include "hda_local.h"
@@ -51,7 +52,16 @@ static int get_wcap_ioctl(struct hda_codec *codec,
if (get_user(verb, &arg->verb))
return -EFAULT;
- res = get_wcaps(codec, verb >> 24);
+ /* open-code get_wcaps(verb>>24) with nospec */
+ verb >>= 24;
+ if (verb < codec->core.start_nid ||
+ verb >= codec->core.start_nid + codec->core.num_nodes) {
+ res = 0;
+ } else {
+ verb -= codec->core.start_nid;
+ verb = array_index_nospec(verb, codec->core.num_nodes);
+ res = codec->wcaps[verb];
+ }
if (put_user(res, &arg->res))
return -EFAULT;
return 0;