ALSA: asihpi: Hardening for potential Spectre v1

As recently Smatch suggested, a couple of places in ASIHPI driver may
expand the array directly from the user-space value with speculation:
  sound/pci/asihpi/hpimsginit.c:70 hpi_init_response() warn: potential spectre issue 'res_size' (local cap)
  sound/pci/asihpi/hpioctl.c:189 asihpi_hpi_ioctl() warn: potential spectre issue 'adapters'

This patch puts array_index_nospec() for hardening against them.

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>
This commit is contained in:
Takashi Iwai 2018-04-24 08:01:48 +02:00
parent 7f054a5bee
commit f9d94b57e3
2 changed files with 12 additions and 5 deletions

View file

@ -23,6 +23,7 @@
#include "hpi_internal.h"
#include "hpimsginit.h"
#include <linux/nospec.h>
/* The actual message size for each object type */
static u16 msg_size[HPI_OBJ_MAXINDEX + 1] = HPI_MESSAGE_SIZE_BY_OBJECT;
@ -39,10 +40,12 @@ static void hpi_init_message(struct hpi_message *phm, u16 object,
{
u16 size;
if ((object > 0) && (object <= HPI_OBJ_MAXINDEX))
if ((object > 0) && (object <= HPI_OBJ_MAXINDEX)) {
object = array_index_nospec(object, HPI_OBJ_MAXINDEX + 1);
size = msg_size[object];
else
} else {
size = sizeof(*phm);
}
memset(phm, 0, size);
phm->size = size;
@ -66,10 +69,12 @@ void hpi_init_response(struct hpi_response *phr, u16 object, u16 function,
{
u16 size;
if ((object > 0) && (object <= HPI_OBJ_MAXINDEX))
if ((object > 0) && (object <= HPI_OBJ_MAXINDEX)) {
object = array_index_nospec(object, HPI_OBJ_MAXINDEX + 1);
size = res_size[object];
else
} else {
size = sizeof(*phr);
}
memset(phr, 0, sizeof(*phr));
phr->size = size;

View file

@ -33,6 +33,7 @@
#include <linux/stringify.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/nospec.h>
#ifdef MODULE_FIRMWARE
MODULE_FIRMWARE("asihpi/dsp5000.bin");
@ -186,7 +187,8 @@ long asihpi_hpi_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct hpi_adapter *pa = NULL;
if (hm->h.adapter_index < ARRAY_SIZE(adapters))
pa = &adapters[hm->h.adapter_index];
pa = &adapters[array_index_nospec(hm->h.adapter_index,
ARRAY_SIZE(adapters))];
if (!pa || !pa->adapter || !pa->adapter->type) {
hpi_init_response(&hr->r0, hm->h.object,