can: raw: raw_setsockopt: limit number of can_filter that can be set
commit 332b05ca7a438f857c61a3c21a88489a21532364 upstream.
This patch adds a check to limit the number of can_filters that can be
set via setsockopt on CAN_RAW sockets. Otherwise allocations > MAX_ORDER
are not prevented resulting in a warning.
Reference: https://lkml.org/lkml/2016/12/2/230
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h
index 9692cda..c48d93a 100644
--- a/include/uapi/linux/can.h
+++ b/include/uapi/linux/can.h
@@ -196,5 +196,6 @@
};
#define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
+#define CAN_RAW_FILTER_MAX 512 /* maximum number of can_filter set via setsockopt() */
#endif /* !_UAPI_CAN_H */
diff --git a/net/can/raw.c b/net/can/raw.c
index 2e67b14..56af689 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -499,6 +499,9 @@
if (optlen % sizeof(struct can_filter) != 0)
return -EINVAL;
+ if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
+ return -EINVAL;
+
count = optlen / sizeof(struct can_filter);
if (count > 1) {
