[PATCH AUTOSEL 4.19 02/15] net: macb: fix use after free on rmmod

Sasha Levin
2021-09-23T03:41:13Z

From: Tong Zhang <ztong0001@gmail.com>

[ Upstream commit d82d5303c4c539db86588ffb5dc5b26c3f1513e8 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/cadence/macb_pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb_pci.c b/drivers/net/ethernet/cadence/macb_pci.c
index 248a8fc45069..f06fddf9919b 100644
--- a/drivers/net/ethernet/cadence/macb_pci.c
+++ b/drivers/net/ethernet/cadence/macb_pci.c
@@ -123,9 +123,9 @@ 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[] = {
--
2.30.2