slot can be controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability,
as warned by smatch:
drivers/media/dvb-core/dvb_ca_en50221.c:1479 dvb_ca_en50221_io_write()
warn: potential spectre issue 'ca->slot_info' (local cap)
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
---
drivers/media/dvb-core/dvb_ca_en50221.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c
b/drivers/media/dvb-core/dvb_ca_en50221.c
index 97365a863519..1310526b0d49 100644
--- a/drivers/media/dvb-core/dvb_ca_en50221.c
+++ b/drivers/media/dvb-core/dvb_ca_en50221.c
@@ -31,6 +31,7 @@
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
+#include <linux/nospec.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
@@ -1476,6 +1477,7 @@ static ssize_t dvb_ca_en50221_io_write(struct file *file,
if (slot >= ca->slot_count)
return -EINVAL;
+ slot = array_index_nospec(slot, ca->slot_count);
sl = &ca->slot_info[slot];
/* check if the slot is actually running */
--
2.17.0
