[PATCH 3.10 029/268] can: raw: raw_setsockopt: limit number of can_filter that can be set

Willy Tarreau
2017-06-19T19:18:36Z

From: Marc Kleine-Budde <mkl@pengutronix.de>

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: Willy Tarreau <w@1wt.eu>
---
include/uapi/linux/can.h | 1 +
net/can/raw.c | 3 +++
2 files changed, 4 insertions(+)

diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h
index e52958d..3018528 100644
--- a/include/uapi/linux/can.h
+++ b/include/uapi/linux/can.h
@@ -158,5 +158,6 @@ 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 /* CAN_H */
diff --git a/net/can/raw.c b/net/can/raw.c
index f4d8648..602be0e 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -470,6 +470,9 @@ 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) {
--
2.8.0.rc2.1.gbe9624a