From: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Date: Tue, 2 Dec 2014 07:54:19 +0000 (+0100)
Subject: clk: Don't try to use a struct clk* after it could have been freed
X-Git-Tag: v3.18.4~96
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=fcdb6d6101c937dd590cfc15c8bcd8a45048fe4f;p=platform%2Fkernel%2Flinux-stable.git

clk: Don't try to use a struct clk* after it could have been freed

commit 10cdfe54dab034311c8e2fad9ba2dffbe616caa9 upstream.

As __clk_release could call kfree on clk and then we wouldn't have a safe way
of getting the module that owns the clock.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Fixes: fcb0ee6a3d33 ("clk: Implement clk_unregister")
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 2a4e8f46010e..26bed0889e97 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2274,14 +2274,17 @@ int __clk_get(struct clk *clk)
 
 void __clk_put(struct clk *clk)
 {
+	struct module *owner;
+
 	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
 		return;
 
 	clk_prepare_lock();
+	owner = clk->owner;
 	kref_put(&clk->ref, __clk_release);
 	clk_prepare_unlock();
 
-	module_put(clk->owner);
+	module_put(owner);
 }
 
 /***        clk rate change notifiers        ***/