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| author | Oleksij Rempel <o.rempel@pengutronix.de> | 2021-02-23 10:01:26 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-02-25 01:32:15 +0300 |
| commit | 4e096a18867a5a989b510f6999d9c6b6622e8f7b (patch) | |
| tree | 1340eb5e6266f2a29d1afe078cce883837e6a02f /include/linux/netdevice.h | |
| parent | 88eee9b7b42e69fb622ddb3ff6f37e8e4347f5b2 (diff) | |
| download | linux-4e096a18867a5a989b510f6999d9c6b6622e8f7b.tar.xz | |
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 'include/linux/netdevice.h')
| -rw-r--r-- | include/linux/netdevice.h | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ddf4cfc12615..f06fbee8638e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1584,6 +1584,12 @@ enum netdev_priv_flags { #define IFF_L3MDEV_RX_HANDLER IFF_L3MDEV_RX_HANDLER #define IFF_LIVE_RENAME_OK IFF_LIVE_RENAME_OK +/* Specifies the type of the struct net_device::ml_priv pointer */ +enum netdev_ml_priv_type { + ML_PRIV_NONE, + ML_PRIV_CAN, +}; + /** * struct net_device - The DEVICE structure. * @@ -1779,6 +1785,7 @@ enum netdev_priv_flags { * @nd_net: Network namespace this network device is inside * * @ml_priv: Mid-layer private + * @ml_priv_type: Mid-layer private type * @lstats: Loopback statistics * @tstats: Tunnel statistics * @dstats: Dummy statistics @@ -2094,8 +2101,10 @@ struct net_device { possible_net_t nd_net; /* mid-layer private */ + void *ml_priv; + enum netdev_ml_priv_type ml_priv_type; + union { - void *ml_priv; struct pcpu_lstats __percpu *lstats; struct pcpu_sw_netstats __percpu *tstats; struct pcpu_dstats __percpu *dstats; @@ -2286,6 +2295,29 @@ static inline void netdev_reset_rx_headroom(struct net_device *dev) netdev_set_rx_headroom(dev, -1); } +static inline void *netdev_get_ml_priv(struct net_device *dev, + enum netdev_ml_priv_type type) +{ + if (dev->ml_priv_type != type) + return NULL; + + return dev->ml_priv; +} + +static inline void netdev_set_ml_priv(struct net_device *dev, + void *ml_priv, + enum netdev_ml_priv_type type) +{ + WARN(dev->ml_priv_type && dev->ml_priv_type != type, + "Overwriting already set ml_priv_type (%u) with different ml_priv_type (%u)!\n", + dev->ml_priv_type, type); + WARN(!dev->ml_priv_type && dev->ml_priv, + "Overwriting already set ml_priv and ml_priv_type is ML_PRIV_NONE!\n"); + + dev->ml_priv = ml_priv; + dev->ml_priv_type = type; +} + /* * Net namespace inlines */ |