linux_dsm_epyc7002/net/can/j1939
Oleksij Rempel 1a5751d58b net: introduce CAN specific pointer in the struct net_device
[ Upstream commit 4e096a18867a5a989b510f6999d9c6b6622e8f7b ]

Since 20dd3850bc ("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: 20dd3850bc ("can: Speed up CAN frame receiption by using ml_priv")
Fixes: ffd956eef6 ("can: introduce CAN midlayer private and allocate it automatically")
Fixes: 9d71dd0c70 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07 15:00:07 +02:00
..
address-claim.c can: add support of SAE J1939 protocol 2019-09-04 14:22:33 +02:00
bus.c can: add support of SAE J1939 protocol 2019-09-04 14:22:33 +02:00
j1939-priv.h can: add support of SAE J1939 protocol 2019-09-04 14:22:33 +02:00
Kconfig can: add support of SAE J1939 protocol 2019-09-04 14:22:33 +02:00
main.c net: introduce CAN specific pointer in the struct net_device 2021-04-07 15:00:07 +02:00
Makefile can: add support of SAE J1939 protocol 2019-09-04 14:22:33 +02:00
socket.c net: introduce CAN specific pointer in the struct net_device 2021-04-07 15:00:07 +02:00
transport.c net: j1939: j1939_session_fresh_new(): fix missing initialization of skbcnt 2020-10-08 23:28:09 +02:00