bus: hisi_lpc: Unregister logical PIO range to avoid potential use-after-free
authorJohn Garry <john.garry@huawei.com>
Tue, 30 Jul 2019 13:29:55 +0000 (21:29 +0800)
committerWei Xu <xuwei5@hisilicon.com>
Tue, 13 Aug 2019 06:54:28 +0000 (14:54 +0800)
commit1b15a5632a809ab57d403fd972ca68785363b654
tree375b953135e98f173555d13711187bf123c62cd1
parentb884e2de2afc68ce30f7093747378ef972dde253
bus: hisi_lpc: Unregister logical PIO range to avoid potential use-after-free

If, after registering a logical PIO range, the driver probe later fails,
the logical PIO range memory will be released automatically.

This causes an issue, in that the logical PIO range is not unregistered
and the released range memory may be later referenced.

Fix by unregistering the logical PIO range.

And since we now unregister the logical PIO range for probe failure, avoid
the special ordering of setting logical PIO range ops, which was the
previous (poor) attempt at a safeguard against this.

Cc: stable@vger.kernel.org
Fixes: adf38bb0b595 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings")
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>
drivers/bus/hisi_lpc.c