linux/net/can
Ziyang Xuan ee8b94c851 can: raw: fix receiver memory leak
Got kmemleak errors with the following ltp can_filter testcase:

for ((i=1; i<=100; i++))
do
        ./can_filter &
        sleep 0.1
done

==============================================================
[<00000000db4a4943>] can_rx_register+0x147/0x360 [can]
[<00000000a289549d>] raw_setsockopt+0x5ef/0x853 [can_raw]
[<000000006d3d9ebd>] __sys_setsockopt+0x173/0x2c0
[<00000000407dbfec>] __x64_sys_setsockopt+0x61/0x70
[<00000000fd468496>] do_syscall_64+0x33/0x40
[<00000000b7e47d51>] entry_SYSCALL_64_after_hwframe+0x61/0xc6

It's a bug in the concurrent scenario of unregister_netdevice_many()
and raw_release() as following:

             cpu0                                        cpu1
unregister_netdevice_many(can_dev)
  unlist_netdevice(can_dev) // dev_get_by_index() return NULL after this
  net_set_todo(can_dev)
						raw_release(can_socket)
						  dev = dev_get_by_index(, ro->ifindex); // dev == NULL
						  if (dev) { // receivers in dev_rcv_lists not free because dev is NULL
						    raw_disable_allfilters(, dev, );
						    dev_put(dev);
						  }
						  ...
						  ro->bound = 0;
						  ...

call_netdevice_notifiers(NETDEV_UNREGISTER, )
  raw_notify(, NETDEV_UNREGISTER, )
    if (ro->bound) // invalid because ro->bound has been set 0
      raw_disable_allfilters(, dev, ); // receivers in dev_rcv_lists will never be freed

Add a net_device pointer member in struct raw_sock to record bound
can_dev, and use rtnl_lock to serialize raw_socket members between
raw_bind(), raw_release(), raw_setsockopt() and raw_notify(). Use
ro->dev to decide whether to free receivers in dev_rcv_lists.

Fixes: 8d0caedb75 ("can: bcm/raw/isotp: use per module netdevice notifier")
Reviewed-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Link: https://lore.kernel.org/all/20230711011737.1969582-1-william.xuanziyang@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2023-07-17 09:23:31 +02:00
..
j1939 sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
af_can.c net: af_can: remove useless parameter 'err' in 'can_rx_register()' 2022-12-12 11:41:24 +01:00
af_can.h can: introduce CAN midlayer private and allocate it automatically 2019-09-04 13:29:14 +02:00
bcm.c sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
gw.c can: gw: give feedback on missing CGW_FLAGS_CAN_IIF_TX_OK flag 2023-02-02 15:42:10 +01:00
isotp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-06-27 09:45:22 -07:00
Kconfig net: Kconfig: move the CAN device menu to the "Device Drivers" section 2022-06-11 17:11:02 +02:00
Makefile can: add ISO 15765-2:2016 transport protocol 2020-10-07 23:18:33 +02:00
proc.c proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
raw.c can: raw: fix receiver memory leak 2023-07-17 09:23:31 +02:00