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| author | Oleksij Rempel <o.rempel@pengutronix.de> | 2021-02-23 08:01:26 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-02-24 14:32:15 -0800 |
| commit | 4e096a18867a5a989b510f6999d9c6b6622e8f7b (patch) | |
| tree | 1340eb5e6266f2a29d1afe078cce883837e6a02f /net/can/proc.c | |
| parent | 88eee9b7b42e69fb622ddb3ff6f37e8e4347f5b2 (diff) | |
| download | linux-4e096a18867a5a989b510f6999d9c6b6622e8f7b.tar.gz linux-4e096a18867a5a989b510f6999d9c6b6622e8f7b.tar.bz2 linux-4e096a18867a5a989b510f6999d9c6b6622e8f7b.zip | |
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/can/proc.c')
| -rw-r--r-- | net/can/proc.c | 19 |
1 files changed, 13 insertions, 6 deletions
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)); } |