diff options
| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2026-01-09 15:41:35 +0100 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2026-01-15 09:52:04 +0100 |
| commit | faba5860fcf9a0ae49d2e484397bce44293367ff (patch) | |
| tree | 94d76c6d98fec1cbc4213cd1c341bece70d8b7c3 | |
| parent | 166e87329ce6f1eaa3475ba2d14ed30e54727c0d (diff) | |
can: raw: instantly reject disabled CAN frames
For real CAN interfaces the CAN_CTRLMODE_FD and CAN_CTRLMODE_XL control
modes indicate whether an interface can handle those CAN FD/XL frames.
In the case a CAN XL interface is configured in CANXL-only mode with
disabled error-signalling neither CAN CC nor CAN FD frames can be sent.
The checks are now performed on CAN_RAW sockets to give an instant feedback
to the user when writing unsupported CAN frames to the interface or when
the CAN interface is in read-only mode.
Fixes: 1a620a723853 ("can: raw: instantly reject unsupported CAN frames")
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260109144135.8495-4-socketcan@hartkopp.net
[mkl: fix dev reference leak]
Link: https://lore.kernel.org/all/0636c732-2e71-4633-8005-dfa85e1da445@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
| -rw-r--r-- | net/can/raw.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/net/can/raw.c b/net/can/raw.c index f36a83d3447c..12293363413c 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -49,8 +49,8 @@ #include <linux/if_arp.h> #include <linux/skbuff.h> #include <linux/can.h> +#include <linux/can/can-ml.h> #include <linux/can/core.h> -#include <linux/can/dev.h> /* for can_is_canxl_dev_mtu() */ #include <linux/can/skb.h> #include <linux/can/raw.h> #include <net/sock.h> @@ -892,20 +892,21 @@ static void raw_put_canxl_vcid(struct raw_sock *ro, struct sk_buff *skb) } } -static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu) +static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb, + struct net_device *dev) { - /* Classical CAN -> no checks for flags and device capabilities */ - if (can_is_can_skb(skb)) + /* Classical CAN */ + if (can_is_can_skb(skb) && can_cap_enabled(dev, CAN_CAP_CC)) return CAN_MTU; - /* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */ + /* CAN FD */ if (ro->fd_frames && can_is_canfd_skb(skb) && - (mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu))) + can_cap_enabled(dev, CAN_CAP_FD)) return CANFD_MTU; - /* CAN XL -> needs to be enabled and a CAN XL device */ + /* CAN XL */ if (ro->xl_frames && can_is_canxl_skb(skb) && - can_is_canxl_dev_mtu(mtu)) + can_cap_enabled(dev, CAN_CAP_XL)) return CANXL_MTU; return 0; @@ -944,6 +945,12 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) if (!dev) return -ENXIO; + /* no sending on a CAN device in read-only mode */ + if (can_cap_enabled(dev, CAN_CAP_RO)) { + err = -EACCES; + goto put_dev; + } + skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv), msg->msg_flags & MSG_DONTWAIT, &err); if (!skb) @@ -961,7 +968,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) err = -EINVAL; /* check for valid CAN (CC/FD/XL) frame content */ - txmtu = raw_check_txframe(ro, skb, READ_ONCE(dev->mtu)); + txmtu = raw_check_txframe(ro, skb, dev); if (!txmtu) goto free_skb; |