net: macb: fix use after free on rmmod

plat_dev->dev->platform_data is released by platform_device_unregister(),
use of pclk and hclk is a use-after-free. Since device unregister won't
need a clk device we adjust the function call sequence to fix this issue.

[   31.261225] BUG: KASAN: use-after-free in macb_remove+0x77/0xc6 [macb_pci]
[   31.275563] Freed by task 306:
[   30.276782]  platform_device_release+0x25/0x80

Suggested-by: Nicolas Ferre <Nicolas.Ferre@microchip.com>
Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/cadence/macb_pci.c b/drivers/net/ethernet/cadence/macb_pci.c
index 8b7b59908a1ab453a9afc4940d3a76779dc750be..f66d22de5168d2be6583f2b78d43a2003ab874c7 100644 (file)
--- a/drivers/net/ethernet/cadence/macb_pci.c
+++ b/drivers/net/ethernet/cadence/macb_pci.c
@@ -111,9 +111,9 @@ static void macb_remove(struct pci_dev *pdev)
        struct platform_device *plat_dev = pci_get_drvdata(pdev);
        struct macb_platform_data *plat_data = dev_get_platdata(&plat_dev->dev);
 
-       platform_device_unregister(plat_dev);
        clk_unregister(plat_data->pclk);
        clk_unregister(plat_data->hclk);
+       platform_device_unregister(plat_dev);
 }
 
 static const struct pci_device_id dev_id_table[] = {