[PATCH 05/38] media: wl128x: get rid of a potential spectre issue

From: Mauro Carvalho Chehab
Date: Wed Sep 02 2020 - 12:11:03 EST


As reported by smatch:
drivers/media/radio/wl128x/fmdrv_common.c:736 fm_irq_handle_rdsdata_getcmd_resp() warn: potential spectre issue 'rds_fmt.data.groupdatabuff.buff>

Address it by using array_index_nospec().

While here, reorder the linux/ includes.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---
drivers/media/radio/wl128x/fmdrv_common.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/media/radio/wl128x/fmdrv_common.c b/drivers/media/radio/wl128x/fmdrv_common.c
index 5c395da74e17..9abc8e0283c1 100644
--- a/drivers/media/radio/wl128x/fmdrv_common.c
+++ b/drivers/media/radio/wl128x/fmdrv_common.c
@@ -19,9 +19,11 @@
* Author: Manjunatha Halli <manjunatha_halli@xxxxxx>
*/

-#include <linux/module.h>
-#include <linux/firmware.h>
#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/module.h>
+#include <linux/nospec.h>
+
#include "fmdrv.h"
#include "fmdrv_v4l2.h"
#include "fmdrv_common.h"
@@ -700,7 +702,7 @@ static void fm_irq_handle_rdsdata_getcmd_resp(struct fmdev *fmdev)
struct fm_rds *rds = &fmdev->rx.rds;
unsigned long group_idx, flags;
u8 *rds_data, meta_data, tmpbuf[FM_RDS_BLK_SIZE];
- u8 type, blk_idx;
+ u8 type, blk_idx, idx;
u16 cur_picode;
u32 rds_len;

@@ -733,9 +735,11 @@ static void fm_irq_handle_rdsdata_getcmd_resp(struct fmdev *fmdev)
}

/* Skip checkword (control) byte and copy only data byte */
- memcpy(&rds_fmt.data.groupdatabuff.
- buff[blk_idx * (FM_RDS_BLK_SIZE - 1)],
- rds_data, (FM_RDS_BLK_SIZE - 1));
+ idx = array_index_nospec(blk_idx * (FM_RDS_BLK_SIZE - 1),
+ FM_RX_RDS_INFO_FIELD_MAX - (FM_RDS_BLK_SIZE - 1));
+
+ memcpy(&rds_fmt.data.groupdatabuff.buff[idx], rds_data,
+ FM_RDS_BLK_SIZE - 1);

rds->last_blk_idx = blk_idx;

--
2.26.2