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authorOleksij Rempel <o.rempel@pengutronix.de>2021-02-23 10:01:26 +0300
committerJakub Kicinski <kuba@kernel.org>2021-02-25 01:32:15 +0300
commit4e096a18867a5a989b510f6999d9c6b6622e8f7b (patch)
tree1340eb5e6266f2a29d1afe078cce883837e6a02f /drivers/net/can/slcan.c
parent88eee9b7b42e69fb622ddb3ff6f37e8e4347f5b2 (diff)
downloadlinux-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 'drivers/net/can/slcan.c')
-rw-r--r--drivers/net/can/slcan.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index a1bd1be09548..30c8d53c9745 100644
--- a/drivers/net/can/slcan.c
+++ b/drivers/net/can/slcan.c
@@ -516,6 +516,7 @@ static struct slcan *slc_alloc(void)
int i;
char name[IFNAMSIZ];
struct net_device *dev = NULL;
+ struct can_ml_priv *can_ml;
struct slcan *sl;
int size;
@@ -538,7 +539,8 @@ static struct slcan *slc_alloc(void)
dev->base_addr = i;
sl = netdev_priv(dev);
- dev->ml_priv = (void *)sl + ALIGN(sizeof(*sl), NETDEV_ALIGN);
+ can_ml = (void *)sl + ALIGN(sizeof(*sl), NETDEV_ALIGN);
+ can_set_ml_priv(dev, can_ml);
/* Initialize channel control data */
sl->magic = SLCAN_MAGIC;