15f3b89bd5
[ Upstream commit afe7116f6d3b888778ed6d95e3cf724767b9aedf ]
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 commit 3e0588c291d6 ("hamradio: defer
ax25 kfree after unregister_netdev") which let the
ieee802154_unregister_hw() to handle the synchronization. This patch
takes the second option.
Fixes: 58e9683d1475 ("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>
Linux kernel
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