net: qcom/emac: Fix use after free bug in emac_remove due to race condition
In emac_probe, &adpt->work_thread is bound with
emac_work_thread. Then it will be started by timeout
handler emac_tx_timeout or a IRQ handler emac_isr.
If we remove the driver which will call emac_remove
to make cleanup, there may be a unfinished work.
The possible sequence is as follows:
Fix it by finishing the work before cleanup in the emac_remove
and disable timeout response.
CPU0 CPU1
|emac_work_thread
emac_remove |
free_netdev |
kfree(netdev); |
|emac_reinit_locked
|emac_mac_down
|//use netdev
Fixes:
b9b17debc69d ("net: emac: emac gigabit ethernet controller driver")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>