From: Marc Kleine-Budde <mkl@pengutronix.de>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org,
kernel@pengutronix.de, Oliver Hartkopp <socketcan@hartkopp.net>,
stable@kernel.org, Oleksij Rempel <o.rempel@pengutronix.de>,
Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH net 04/16] can: convert unreliable ARPHRD_CAN type checks to robust can_get_ml_priv()
Date: Tue, 29 Sep 2026 22:43:54 +0200 [thread overview]
Message-ID: <20260929210700.1183036-5-mkl@pengutronix.de> (raw)
In-Reply-To: <20260929210700.1183036-1-mkl@pengutronix.de>
From: Oliver Hartkopp <socketcan@hartkopp.net>
Commit 4e096a18867a ("net: introduce CAN specific pointer in the struct
net_device") introduced an explicit way to assign the midlayer private
pointer (dev->ml_priv) to named users like ML_PRIV_CAN.
With this extension the CAN device specific ml_priv assignment became a
robust indicator to identify a valid CAN device, when can_get_ml_priv()
returns a valid pointer.
This has been used directly by the referenced commit in the CAN specific
j1939 and proc code but not in the other parts of the CAN subsystem.
With the TUN/TAP driver a device's ARPHRD type can be controlled by
userspace independently of its midlayer private data (ml_priv). The
TUNSETLINK ioctl allows a down TUN/TAP device to overwrite its hardware
type to become ARPHRD_CAN while dev->ml_priv remains NULL (uninitialized).
Instead of checking dev->type being the unreliable ARPHRD_CAN value convert
the missing "valid CAN devices" checks to can_get_ml_priv().
Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device")
Cc: stable@kernel.org
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260929163424.16382-3-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
net/can/af_can.c | 12 ++++++------
net/can/bcm.c | 7 ++++---
net/can/gw.c | 7 ++++---
net/can/isotp.c | 5 +++--
net/can/raw.c | 4 ++--
5 files changed, 19 insertions(+), 16 deletions(-)
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 7bc86b176b4d..ef435f22ac93 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -226,7 +226,7 @@ int can_send(struct sk_buff *skb, int loop)
goto inval_skb;
}
- if (unlikely(skb->dev->type != ARPHRD_CAN)) {
+ if (unlikely(!can_get_ml_priv(skb->dev))) {
err = -EPERM;
goto inval_skb;
}
@@ -452,7 +452,7 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
/* insert new receiver (dev,canid,mask) -> (func,data) */
- if (dev && (dev->type != ARPHRD_CAN || !can_get_ml_priv(dev)))
+ if (dev && !can_get_ml_priv(dev))
return -ENODEV;
if (dev && !net_eq(net, dev_net(dev)))
@@ -519,7 +519,7 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
struct can_dev_rcv_lists *dev_rcv_lists;
- if (dev && dev->type != ARPHRD_CAN)
+ if (dev && !can_get_ml_priv(dev))
return;
if (dev && !net_eq(net, dev_net(dev)))
@@ -687,7 +687,7 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev)
static int can_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
- if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) ||
+ if (unlikely(!can_get_ml_priv(dev) ||
!can_skb_ext_find(skb) || !can_is_can_skb(skb))) {
pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n",
dev->type, skb->len);
@@ -703,7 +703,7 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev,
static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
- if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) ||
+ if (unlikely(!can_get_ml_priv(dev) ||
!can_skb_ext_find(skb) || !can_is_canfd_skb(skb))) {
pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n",
dev->type, skb->len);
@@ -719,7 +719,7 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
static int canxl_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
- if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) ||
+ if (unlikely(!can_get_ml_priv(dev) ||
!can_skb_ext_find(skb) || !can_is_canxl_skb(skb))) {
pr_warn_once("PF_CAN: dropped non conform CAN XL skbuff: dev type %d, len %d\n",
dev->type, skb->len);
diff --git a/net/can/bcm.c b/net/can/bcm.c
index cd3522ec32c0..940b917e3830 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -54,6 +54,7 @@
#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/skb.h>
#include <linux/can/bcm.h>
@@ -1760,7 +1761,7 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
goto out_release;
}
- if (dev->type != ARPHRD_CAN) {
+ if (!can_get_ml_priv(dev)) {
dev_put(dev);
ret = -ENODEV;
goto out_release;
@@ -1908,7 +1909,7 @@ static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- if (dev->type != ARPHRD_CAN)
+ if (!can_get_ml_priv(dev))
return NOTIFY_DONE;
if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
return NOTIFY_DONE;
@@ -2069,7 +2070,7 @@ static int bcm_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int
ret = -ENODEV;
goto fail;
}
- if (dev->type != ARPHRD_CAN) {
+ if (!can_get_ml_priv(dev)) {
dev_put(dev);
ret = -ENODEV;
goto fail;
diff --git a/net/can/gw.c b/net/can/gw.c
index 0ec99f68aa45..d9912dea738b 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -52,6 +52,7 @@
#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/skb.h>
#include <linux/can/gw.h>
@@ -609,7 +610,7 @@ static int cgw_notifier(struct notifier_block *nb,
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct net *net = dev_net(dev);
- if (dev->type != ARPHRD_CAN)
+ if (!can_get_ml_priv(dev))
return NOTIFY_DONE;
if (msg == NETDEV_UNREGISTER) {
@@ -1160,7 +1161,7 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh,
if (!gwj->src.dev)
goto out;
- if (gwj->src.dev->type != ARPHRD_CAN)
+ if (!can_get_ml_priv(gwj->src.dev))
goto out;
gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx);
@@ -1168,7 +1169,7 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh,
if (!gwj->dst.dev)
goto out;
- if (gwj->dst.dev->type != ARPHRD_CAN)
+ if (!can_get_ml_priv(gwj->dst.dev))
goto out;
/* is sending the skb back to the incoming interface intended? */
diff --git a/net/can/isotp.c b/net/can/isotp.c
index 0835a4758a72..d3f79efc9c1e 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -65,6 +65,7 @@
#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/skb.h>
#include <linux/can/isotp.h>
@@ -1606,7 +1607,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int l
err = -ENODEV;
goto out;
}
- if (dev->type != ARPHRD_CAN) {
+ if (!can_get_ml_priv(dev)) {
err = -ENODEV;
goto out_put_dev;
}
@@ -1890,7 +1891,7 @@ static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- if (dev->type != ARPHRD_CAN)
+ if (!can_get_ml_priv(dev))
return NOTIFY_DONE;
if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
return NOTIFY_DONE;
diff --git a/net/can/raw.c b/net/can/raw.c
index c5596fc9aac5..7c48ff36e6cd 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -341,7 +341,7 @@ static int raw_notifier(struct notifier_block *nb, unsigned long msg,
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- if (dev->type != ARPHRD_CAN)
+ if (!can_get_ml_priv(dev))
return NOTIFY_DONE;
if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
return NOTIFY_DONE;
@@ -484,7 +484,7 @@ static int raw_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int len
err = -ENODEV;
goto out;
}
- if (dev->type != ARPHRD_CAN) {
+ if (!can_get_ml_priv(dev)) {
err = -ENODEV;
goto out_put_dev;
}
--
2.53.0
next prev parent reply other threads:[~2026-09-29 21:07 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-29 20:43 [PATCH net 0/16] pull-request: can 2026-09-29 Marc Kleine-Budde
2026-09-29 20:43 ` [PATCH net 01/16] can: dev: can_dropped_invalid_skb: drop CAN XL frames on non-CAN XL devices Marc Kleine-Budde
2026-09-29 21:13 ` netdev-bot+sinfo
2026-09-29 20:43 ` [PATCH net 02/16] can: dev: init_can_skb(): restore skb header initialization Marc Kleine-Budde
2026-09-29 20:43 ` [PATCH net 03/16] can: remove CAN filters independent from namespace Marc Kleine-Budde
2026-09-29 20:43 ` Marc Kleine-Budde [this message]
2026-09-29 20:43 ` [PATCH net 05/16] can: fix unique skb identifier regression under RPS Marc Kleine-Budde
2026-09-29 20:43 ` [PATCH net 06/16] can: isotp: check the frame type, not just the length Marc Kleine-Budde
2026-09-29 20:43 ` [PATCH net 07/16] can: m_can: pci: add missing pm_runtime_dont_use_autosuspend() call Marc Kleine-Budde
2026-09-29 20:43 ` [PATCH net 08/16] can: xilinx_can: set CAN FD flags on received frames Marc Kleine-Budde
2026-09-29 20:43 ` [PATCH net 09/16] can: mcp251xfd: mcp251xfd_probe(): reject devices without match data Marc Kleine-Budde
2026-09-29 20:44 ` [PATCH net 10/16] usb: f81604: fix struct f81604_int_data size mismatch Marc Kleine-Budde
2026-09-29 20:44 ` [PATCH net 11/16] can: gs_usb: kill RX URBs before destroying the netdevs Marc Kleine-Budde
2026-09-29 20:44 ` [PATCH net 12/16] can: gs_usb: add workarounds for HScanT USB to CAN adapter Marc Kleine-Budde
2026-09-29 20:44 ` [PATCH net 13/16] can: kvaser_usb: validate command format before parsing in hydra receive path Marc Kleine-Budde
2026-09-29 20:44 ` [PATCH net 14/16] can: peak_usb: fix missing CAN_ERR_FLAG when reporting error counters Marc Kleine-Budde
2026-09-29 20:44 ` [PATCH net 15/16] can: rx-offload: add IRQ queue flush predicate Marc Kleine-Budde
2026-09-29 20:44 ` [PATCH net 16/16] can: mcp251xfd: flush RX offload queue during long IRQs Marc Kleine-Budde
2026-10-01 8:40 ` [PATCH net 0/16] pull-request: can 2026-09-29 Paolo Abeni
2026-10-01 9:23 ` Oliver Hartkopp
2026-10-01 10:13 ` Paolo Abeni
2026-10-01 10:28 ` Oliver Hartkopp
2026-10-01 10:55 ` Marc Kleine-Budde
2026-10-01 15:25 ` Jakub Kicinski
2026-10-01 15:38 ` Marc Kleine-Budde
2026-10-01 18:19 ` Jakub Kicinski
2026-10-05 7:28 ` Oliver Hartkopp
2026-10-05 9:20 ` Marc Kleine-Budde
2026-10-05 9:24 ` Oliver Hartkopp
2026-10-05 9:32 ` Marc Kleine-Budde
2026-10-01 15:28 ` Jakub Kicinski
2026-10-01 15:37 ` Marc Kleine-Budde
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