From: Stephen Boyd sboyd@kernel.org
[ Upstream commit d89091a4930ee0d80bee3e259a98513f3a2543ec ]
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 nicolas.ferre@microchip.com Cc: Yash Shah yash.shah@sifive.com Reported-by: Guenter Roeck linux@roeck-us.net Fixes: c218ad559020 ("macb: Add support for SiFive FU540-C000") Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/cadence/macb_main.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
--- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -4027,7 +4027,7 @@ static int fu540_c000_clk_init(struct pl mgmt->rate = 0; mgmt->hw.init = &init;
- *tx_clk = clk_register(NULL, &mgmt->hw); + *tx_clk = devm_clk_register(&pdev->dev, &mgmt->hw); if (IS_ERR(*tx_clk)) return PTR_ERR(*tx_clk);
@@ -4361,7 +4361,6 @@ err_out_free_netdev:
err_disable_clocks: clk_disable_unprepare(tx_clk); - clk_unregister(tx_clk); clk_disable_unprepare(hclk); clk_disable_unprepare(pclk); clk_disable_unprepare(rx_clk); @@ -4397,7 +4396,6 @@ static int macb_remove(struct platform_d pm_runtime_dont_use_autosuspend(&pdev->dev); if (!pm_runtime_suspended(&pdev->dev)) { clk_disable_unprepare(bp->tx_clk); - clk_unregister(bp->tx_clk); clk_disable_unprepare(bp->hclk); clk_disable_unprepare(bp->pclk); clk_disable_unprepare(bp->rx_clk);