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authorOleksij Rempel <o.rempel@pengutronix.de>2021-02-23 08:01:26 +0100
committerJakub Kicinski <kuba@kernel.org>2021-02-24 14:32:15 -0800
commit4e096a18867a5a989b510f6999d9c6b6622e8f7b (patch)
tree1340eb5e6266f2a29d1afe078cce883837e6a02f /net
parent88eee9b7b42e69fb622ddb3ff6f37e8e4347f5b2 (diff)
net: introduce CAN specific pointer in the struct net_device
Since 20dd3850bcf8 ("can: Speed up CAN frame receiption by using ml_priv") the CAN framework uses per device specific data in the AF_CAN protocol. For this purpose the struct net_device->ml_priv is used. Later the ml_priv usage in CAN was extended for other users, one of them being CAN_J1939. Later in the kernel ml_priv was converted to an union, used by other drivers. E.g. the tun driver started storing it's stats pointer. Since tun devices can claim to be a CAN device, CAN specific protocols will wrongly interpret this pointer, which will cause system crashes. Mostly this issue is visible in the CAN_J1939 stack. To fix this issue, we request a dedicated CAN pointer within the net_device struct. Reported-by: syzbot+5138c4dd15a0401bec7b@syzkaller.appspotmail.com Fixes: 20dd3850bcf8 ("can: Speed up CAN frame receiption by using ml_priv") Fixes: ffd956eef69b ("can: introduce CAN midlayer private and allocate it automatically") Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Fixes: 497a5757ce4e ("tun: switch to net core provided statistics counters") Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: https://lore.kernel.org/r/20210223070127.4538-1-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/can/af_can.c34
-rw-r--r--net/can/j1939/main.c22
-rw-r--r--net/can/j1939/socket.c13
-rw-r--r--net/can/proc.c19
4 files changed, 27 insertions, 61 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 837bb8af0ec3..cce2af10eb3e 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -304,8 +304,8 @@ static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net,
struct net_device *dev)
{
if (dev) {
- struct can_ml_priv *ml_priv = dev->ml_priv;
- return &ml_priv->dev_rcv_lists;
+ struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+ return &can_ml->dev_rcv_lists;
} else {
return net->can.rx_alldev_list;
}
@@ -790,25 +790,6 @@ void can_proto_unregister(const struct can_proto *cp)
}
EXPORT_SYMBOL(can_proto_unregister);
-/* af_can notifier to create/remove CAN netdevice specific structs */
-static int can_notifier(struct notifier_block *nb, unsigned long msg,
- void *ptr)
-{
- struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-
- if (dev->type != ARPHRD_CAN)
- return NOTIFY_DONE;
-
- switch (msg) {
- case NETDEV_REGISTER:
- WARN(!dev->ml_priv,
- "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n");
- break;
- }
-
- return NOTIFY_DONE;
-}
-
static int can_pernet_init(struct net *net)
{
spin_lock_init(&net->can.rcvlists_lock);
@@ -876,11 +857,6 @@ static const struct net_proto_family can_family_ops = {
.owner = THIS_MODULE,
};
-/* notifier block for netdevice event */
-static struct notifier_block can_netdev_notifier __read_mostly = {
- .notifier_call = can_notifier,
-};
-
static struct pernet_operations can_pernet_ops __read_mostly = {
.init = can_pernet_init,
.exit = can_pernet_exit,
@@ -911,17 +887,12 @@ static __init int can_init(void)
err = sock_register(&can_family_ops);
if (err)
goto out_sock;
- err = register_netdevice_notifier(&can_netdev_notifier);
- if (err)
- goto out_notifier;
dev_add_pack(&can_packet);
dev_add_pack(&canfd_packet);
return 0;
-out_notifier:
- sock_unregister(PF_CAN);
out_sock:
unregister_pernet_subsys(&can_pernet_ops);
out_pernet:
@@ -935,7 +906,6 @@ static __exit void can_exit(void)
/* protocol unregister */
dev_remove_pack(&canfd_packet);
dev_remove_pack(&can_packet);
- unregister_netdevice_notifier(&can_netdev_notifier);
sock_unregister(PF_CAN);
unregister_pernet_subsys(&can_pernet_ops);
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
index bb914d8b4216..da3a7a7bcff2 100644
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -140,9 +140,9 @@ static struct j1939_priv *j1939_priv_create(struct net_device *ndev)
static inline void j1939_priv_set(struct net_device *ndev,
struct j1939_priv *priv)
{
- struct can_ml_priv *can_ml_priv = ndev->ml_priv;
+ struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
- can_ml_priv->j1939_priv = priv;
+ can_ml->j1939_priv = priv;
}
static void __j1939_priv_release(struct kref *kref)
@@ -211,12 +211,9 @@ static void __j1939_rx_release(struct kref *kref)
/* get pointer to priv without increasing ref counter */
static inline struct j1939_priv *j1939_ndev_to_priv(struct net_device *ndev)
{
- struct can_ml_priv *can_ml_priv = ndev->ml_priv;
+ struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
- if (!can_ml_priv)
- return NULL;
-
- return can_ml_priv->j1939_priv;
+ return can_ml->j1939_priv;
}
static struct j1939_priv *j1939_priv_get_by_ndev_locked(struct net_device *ndev)
@@ -225,9 +222,6 @@ static struct j1939_priv *j1939_priv_get_by_ndev_locked(struct net_device *ndev)
lockdep_assert_held(&j1939_netdev_lock);
- if (ndev->type != ARPHRD_CAN)
- return NULL;
-
priv = j1939_ndev_to_priv(ndev);
if (priv)
j1939_priv_get(priv);
@@ -348,15 +342,16 @@ static int j1939_netdev_notify(struct notifier_block *nb,
unsigned long msg, void *data)
{
struct net_device *ndev = netdev_notifier_info_to_dev(data);
+ struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
struct j1939_priv *priv;
+ if (!can_ml)
+ goto notify_done;
+
priv = j1939_priv_get_by_ndev(ndev);
if (!priv)
goto notify_done;
- if (ndev->type != ARPHRD_CAN)
- goto notify_put;
-
switch (msg) {
case NETDEV_DOWN:
j1939_cancel_active_session(priv, NULL);
@@ -365,7 +360,6 @@ static int j1939_netdev_notify(struct notifier_block *nb,
break;
}
-notify_put:
j1939_priv_put(priv);
notify_done:
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index f23966526a88..56aa66147d5a 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -12,6 +12,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/can/can-ml.h>
#include <linux/can/core.h>
#include <linux/can/skb.h>
#include <linux/errqueue.h>
@@ -453,6 +454,7 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len)
j1939_jsk_del(priv, jsk);
j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
} else {
+ struct can_ml_priv *can_ml;
struct net_device *ndev;
ndev = dev_get_by_index(net, addr->can_ifindex);
@@ -461,15 +463,8 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len)
goto out_release_sock;
}
- if (ndev->type != ARPHRD_CAN) {
- dev_put(ndev);
- ret = -ENODEV;
- goto out_release_sock;
- }
-
- if (!ndev->ml_priv) {
- netdev_warn_once(ndev,
- "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n");
+ can_ml = can_get_ml_priv(ndev);
+ if (!can_ml) {
dev_put(ndev);
ret = -ENODEV;
goto out_release_sock;
diff --git a/net/can/proc.c b/net/can/proc.c
index 5ea8695f507e..b15760b5c1cc 100644
--- a/net/can/proc.c
+++ b/net/can/proc.c
@@ -322,8 +322,11 @@ static int can_rcvlist_proc_show(struct seq_file *m, void *v)
/* receive list for registered CAN devices */
for_each_netdev_rcu(net, dev) {
- if (dev->type == ARPHRD_CAN && dev->ml_priv)
- can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
+ struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+
+ if (can_ml)
+ can_rcvlist_proc_show_one(m, idx, dev,
+ &can_ml->dev_rcv_lists);
}
rcu_read_unlock();
@@ -375,8 +378,10 @@ static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
/* sff receive list for registered CAN devices */
for_each_netdev_rcu(net, dev) {
- if (dev->type == ARPHRD_CAN && dev->ml_priv) {
- dev_rcv_lists = dev->ml_priv;
+ struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+
+ if (can_ml) {
+ dev_rcv_lists = &can_ml->dev_rcv_lists;
can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_sff,
ARRAY_SIZE(dev_rcv_lists->rx_sff));
}
@@ -406,8 +411,10 @@ static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
/* eff receive list for registered CAN devices */
for_each_netdev_rcu(net, dev) {
- if (dev->type == ARPHRD_CAN && dev->ml_priv) {
- dev_rcv_lists = dev->ml_priv;
+ struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+
+ if (can_ml) {
+ dev_rcv_lists = &can_ml->dev_rcv_lists;
can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_eff,
ARRAY_SIZE(dev_rcv_lists->rx_eff));
}