From: Conor Dooley <conor.dooley@microchip.com>
Date: Thu, 13 Apr 2023 23:20:45 +0100
Subject: [PATCH] clk: microchip: fix potential UAF in auxdev release callback
References: bsc#1012628
Patch-mainline: 6.3.2
Git-commit: 7455b7007b9e93bcc2bc9c1c6c73a228e3152069

commit 7455b7007b9e93bcc2bc9c1c6c73a228e3152069 upstream.

Similar to commit 1c11289b34ab ("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: b56bae2dd6fd ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/clk/microchip/clk-mpfs.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/clk/microchip/clk-mpfs.c b/drivers/clk/microchip/clk-mpfs.c
index 4f0a19db..cc5d7dee 100644
--- a/drivers/clk/microchip/clk-mpfs.c
+++ b/drivers/clk/microchip/clk-mpfs.c
@@ -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);
 }
 
-- 
2.35.3