[PATCH 1/2] clk: fix clk not being unlinked from consumers list

["Nuno Sá" <nuno.sa@analog.com>]

When a clk_hw is registered we add a struct clk handle to it's
consumers list. This handle is created in '__clk_register()' per the
'alloc_clk()' call.

As such, we need to remove this handle when unregistering the
clk_hw. This can actually lead to a use after free if a provider gets
removed before a consumer. When removing the consumer, '__clk_put()' is
called and that will do 'hlist_del(&clk->clks_node)' which will touch in
already freed memory.

Fixes: 1df4046a93e0 ("clk: Combine __clk_get() and __clk_create_clk()")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
 drivers/clk/clk.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 8cca52be993f..b11beeca7e55 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -4606,6 +4606,8 @@ void clk_unregister(struct clk *clk)
 	if (clk->core->protect_count)
 		pr_warn("%s: unregistering protected clock: %s\n",
 					__func__, clk->core->name);
+
+	clk_core_unlink_consumer(clk);
 	clk_prepare_unlock();
 
 	kref_put(&clk->core->ref, __clk_release);

-- 
2.45.2