Commit 29fd2a34 authored Dec 19, 2017 by Jerome Brunet Committed by Michael Turquette Dec 19, 2017

clk: check ops pointer on clock register



Nothing really prevents a provider from (trying to) register a clock
without providing the clock ops structure.

We do check the individual fields before using them, but not the
structure pointer itself. This may have the usual nasty consequences when
the pointer is dereferenced, most likely when checking one the field
during the initialization.

This is fixed by returning an error on clock register if the ops pointer
is NULL.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20171219083329.24746-1-jbrunet@baylibre.com

parent 4fbd8d19

drivers/clk/clk.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -2678,7 +2678,13 @@ struct clk clk_register(struct device dev, struct clk_hw *hw)
		ret = -ENOMEM;
		goto fail_name;
		}

		if (WARN_ON(!hw->init->ops)) {
		ret = -EINVAL;
		goto fail_ops;
		}
		core->ops = hw->init->ops;

		if (dev && pm_runtime_enabled(dev))
		core->dev = dev;
		if (dev && dev->driver)
		@@ -2740,6 +2746,7 @@ fail_parent_names_copy:
		kfree_const(core->parent_names[i]);
		kfree(core->parent_names);
		fail_parent_names:
		fail_ops:
		kfree_const(core->name);
		fail_name:
		kfree(core);

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