4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jerome Brunet <[email protected]>


[ Upstream commit 29fd2a34ef8d863e48183bd473ba57c8d7839e25 ]

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 <[email protected]>
Signed-off-by: Michael Turquette <[email protected]>
Link: lkml.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 drivers/clk/clk.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2684,7 +2684,13 @@ struct clk *clk_register(struct device *
                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)
@@ -2746,6 +2752,7 @@ 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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