linux

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Lin Ma 9873fe0f38 hamradio: remove needs_free_netdev to avoid UAF

commit 81b1d548d00bcd028303c4f3150fa753b9b8aa71 upstream.

The former patch "defer 6pack kfree after unregister_netdev" reorders
the kfree of two buffer after the unregister_netdev to prevent the race
condition. It also adds free_netdev() function in sixpack_close(), which
is a direct copy from the similar code in mkiss_close().

However, in sixpack driver, the flag needs_free_netdev is set to true in
sp_setup(), hence the unregister_netdev() will free the netdev
automatically. Therefore, as the sp is netdev_priv, use-after-free
occurs.

This patch removes the needs_free_netdev = true and just let the
free_netdev to finish this deallocation task.

Fixes: 0b9111922b1f ("hamradio: defer 6pack kfree after unregister_netdev")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Link: https://lore.kernel.org/r/20211111141402.7551-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Xu Jia <xujia39@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2022-04-20 09:34:04 +02:00

6pack.c

hamradio: remove needs_free_netdev to avoid UAF

2022-04-20 09:34:04 +02:00

baycom_epp.c

hamradio: baycom_epp: fix build for UML

2021-10-18 12:57:42 +01:00

baycom_par.c

hamradio: use ndo_siocdevprivate

2021-07-27 20:11:44 +01:00

baycom_ser_fdx.c

hamradio: use ndo_siocdevprivate