Re: [PATCH v2] mwifiex: fix possible NULL dereference

From: Arend van Spriel
Date: Tue Apr 12 2016 - 07:50:51 EST




On 12-04-16 13:46, Sudip Mukherjee wrote:
> From: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
>
> We have a check for card just after dereferencing it. So if it is NULL
> we have already dereferenced it before its check. Lets dereference it
> after checking card for NULL.

And you are changing the scope of the pdev variable.

Regards,
Arend

> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
> ---
> drivers/net/wireless/marvell/mwifiex/pcie.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c
> index edf8b07..d4db9db 100644
> --- a/drivers/net/wireless/marvell/mwifiex/pcie.c
> +++ b/drivers/net/wireless/marvell/mwifiex/pcie.c
> @@ -2884,10 +2884,11 @@ static void mwifiex_unregister_dev(struct mwifiex_adapter *adapter)
> {
> struct pcie_service_card *card = adapter->card;
> const struct mwifiex_pcie_card_reg *reg;
> - struct pci_dev *pdev = card->dev;
> int i;
>
> if (card) {
> + struct pci_dev *pdev = card->dev;
> +
> if (card->msix_enable) {
> for (i = 0; i < MWIFIEX_NUM_MSIX_VECTORS; i++)
> synchronize_irq(card->msix_entries[i].vector);
>