[PATCH 5.18 069/102] epic100: fix use after free on rmmod

Greg Kroah-Hartman
2022-07-05T12:35:27Z

From: Tong Zhang <ztong0001@gmail.com>

commit 8ee9d82cd0a45e7d050ade598c9f33032a0f2891 upstream.

epic_close() calls epic_rx() and uses dma buffer, but in epic_remove_one()
we already freed the dma buffer. To fix this issue, reorder function calls
like in the .probe function.

BUG: KASAN: use-after-free in epic_rx+0xa6/0x7e0 [epic100]
Call Trace:
epic_rx+0xa6/0x7e0 [epic100]
epic_close+0xec/0x2f0 [epic100]
unregister_netdev+0x18/0x20
epic_remove_one+0xaa/0xf0 [epic100]

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Yilun Wu <yiluwu@cs.stonybrook.edu>
Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Reviewed-by: Francois Romieu <romieu@fr.zoreil.com>
Link: https://lore.kernel.org/r/20220627043351.25615-1-ztong0001@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/smsc/epic100.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/smsc/epic100.c
+++ b/drivers/net/ethernet/smsc/epic100.c
@@ -1515,14 +1515,14 @@ static void epic_remove_one(struct pci_d
struct net_device *dev = pci_get_drvdata(pdev);
struct epic_private *ep = netdev_priv(dev);

+ unregister_netdev(dev);
dma_free_coherent(&pdev->dev, TX_TOTAL_SIZE, ep->tx_ring,
ep->tx_ring_dma);
dma_free_coherent(&pdev->dev, RX_TOTAL_SIZE, ep->rx_ring,
ep->rx_ring_dma);
- unregister_netdev(dev);
pci_iounmap(pdev, ep->ioaddr);
- pci_release_regions(pdev);
free_netdev(dev);
+ pci_release_regions(pdev);
pci_disable_device(pdev);
/* pci_power_off(pdev, -1); */
}