can: raw: raw_setsockopt: limit number of can_filter that can be set

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 <[email protected]> Tested-by: Andrey Konovalov <[email protected]> Cc: linux-stable <[email protected]> Signed-off-by: Marc Kleine-Budde <[email protected]>
modi0012 · Dec 7, 2016 · 332b05c · 332b05c
1 parent bc3913a
commit 332b05c
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diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h
@@ -196,5 +196,6 @@ struct can_filter {
 };
 
 #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
@@ -499,6 +499,9 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
 		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) {