On 11.07.2023 09:17:37, Ziyang Xuan wrote:
> 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: 8d0caedb7596 ("can: bcm/raw/isotp: use per module netdevice notifier")
> Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
> Reviewed-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
> Acked-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Added to linux-can/testing.
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
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