From: Oliver Hartkopp socketcan@hartkopp.net

When the socket is CAN FD enabled it can handle CAN FD frame transmissions. Add an additional check in raw_sendmsg() as a CAN2.0 CAN driver (non CAN FD) should never see a CAN FD frame. Due to the commonly used can_dropped_invalid_skb() function the CAN 2.0 driver would drop that CAN FD frame anyway - but with this patch the user gets a proper -EINVAL return code.

Signed-off-by: Oliver Hartkopp socketcan@hartkopp.net Cc: linux-stable stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- net/can/raw.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/net/can/raw.c b/net/can/raw.c index 1051eee82581..3aab7664933f 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -745,18 +745,19 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) } else ifindex = ro->ifindex;

- if (ro->fd_frames) { + dev = dev_get_by_index(sock_net(sk), ifindex); + if (!dev) + return -ENXIO; + + err = -EINVAL; + if (ro->fd_frames && dev->mtu == CANFD_MTU) { if (unlikely(size != CANFD_MTU && size != CAN_MTU)) - return -EINVAL; + goto put_dev; } else { if (unlikely(size != CAN_MTU)) - return -EINVAL; + goto put_dev; }

- dev = dev_get_by_index(sock_net(sk), ifindex); - if (!dev) - return -ENXIO; - skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), msg->msg_flags & MSG_DONTWAIT, &err); if (!skb)