macb: Don't unregister clks unconditionally

The only clk init function in this driver that register a clk is
fu540_c000_clk_init(), and thus we need to unregister the clk when this
driver is removed on that platform. Other init functions, for example
macb_clk_init(), don't register clks and therefore we shouldn't
unregister the clks when this driver is removed. Convert this
registration path to devm so it gets auto-unregistered when this driver
is removed and drop the clk_unregister() calls in driver remove (and
error paths) so that we don't erroneously remove a clk from the system
that isn't registered by this driver.

Otherwise we get strange crashes with a use-after-free when the
devm_clk_get() call in macb_clk_init() calls clk_put() on a clk pointer
that has become invalid because it is freed in clk_unregister().

Cc: Nicolas Ferre <[email protected]>
Cc: Yash Shah <[email protected]>
Reported-by: Guenter Roeck <[email protected]>
Fixes: c218ad559020 ("macb: Add support for SiFive FU540-C000")
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions