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 <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/can/raw.c b/net/can/raw.c
index 972c187d40ab..b075f028d7e2 100644
--- 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) {