9f8558c5c6
[ Upstream commitafe7116f6d] There is a possible race condition (use-after-free) like below (FREE) | (USE) adf7242_remove | adf7242_channel cancel_delayed_work_sync | destroy_workqueue (1) | adf7242_cmd_rx | mod_delayed_work (2) | The root cause for this race is that the upper layer (ieee802154) is unaware of this detaching event and the function adf7242_channel can be called without any checks. To fix this, we can add a flag write at the beginning of adf7242_remove and add flag check in adf7242_channel. Or we can just defer the destructive operation like other commit3e0588c291("hamradio: defer ax25 kfree after unregister_netdev") which let the ieee802154_unregister_hw() to handle the synchronization. This patch takes the second option. Fixes:58e9683d14("net: ieee802154: adf7242: Fix OCL calibration runs") Signed-off-by: Lin Ma <linma@zju.edu.cn> Acked-by: Michael Hennerich <michael.hennerich@analog.com> Link: https://lore.kernel.org/r/20220808034224.12642-1-linma@zju.edu.cn Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org> Signed-off-by: Sasha Levin <sashal@kernel.org>