clk: microchip: fix potential UAF in auxdev release callback

Similar to commit 1c11289b34 ("peci: cpu: Fix use-after-free in
adev_release()"), the auxiliary device is not torn down in the correct
order. If auxiliary_device_add() fails, the release callback will be
called twice, resulting in a UAF. Due to timing, the auxdev code in this
driver "took inspiration" from the aforementioned commit, and thus its
bugs too!

Moving auxiliary_device_uninit() to the unregister callback instead
avoids the issue.

CC: stable@vger.kernel.org
Fixes: b56bae2dd6 ("clk: microchip: mpfs: add reset controller")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230413-critter-synopsis-dac070a86cb4@spud
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This commit is contained in:
Conor Dooley 2023-04-13 23:20:45 +01:00 committed by Stephen Boyd
parent fb8b9d23f1
commit 7455b7007b

View File

@ -374,14 +374,13 @@ static void mpfs_reset_unregister_adev(void *_adev)
struct auxiliary_device *adev = _adev;
auxiliary_device_delete(adev);
auxiliary_device_uninit(adev);
}
static void mpfs_reset_adev_release(struct device *dev)
{
struct auxiliary_device *adev = to_auxiliary_dev(dev);
auxiliary_device_uninit(adev);
kfree(adev);
}