On 11.09.2018 20:38, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> Currently the pointer wilc is being null checked several times
> and yet not checked for the final workqueue flush and destroy
> (which can lead to a null pointer dereference if wilc is null);
> these missing null checks were overlooked in an earlier core
> refactoring commit.
>
> Clean up the code by checking wilc at the start and bailing out
> early if it is null allowing the subsequent null checks to be
> removed, this also fixes the potential null pointer deferences
> on the workqueue flush and destroy calls.
>
> Detected by CoverityScan, CID#1473305 ("Dereference after null check")
>
> Fixes: b3ee105c332e ("staging: wilc1000: refactor code to move initilization in wilc_netdev_init()")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Reviewed-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
> ---
> drivers/staging/wilc1000/linux_wlan.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/wilc1000/linux_wlan.c b/drivers/staging/wilc1000/linux_wlan.c
> index a498321c908b..49afda669393 100644
> --- a/drivers/staging/wilc1000/linux_wlan.c
> +++ b/drivers/staging/wilc1000/linux_wlan.c
> @@ -1015,15 +1015,18 @@ void wilc_netdev_cleanup(struct wilc *wilc)
> {
> int i;
>
> - if (wilc && (wilc->vif[0]->ndev || wilc->vif[1]->ndev))
> + if (!wilc)
> + return;
> +
> + if (wilc->vif[0]->ndev || wilc->vif[1]->ndev)
> unregister_inetaddr_notifier(&g_dev_notifier);
>
> - if (wilc && wilc->firmware) {
> + if (wilc->firmware) {
> release_firmware(wilc->firmware);
> wilc->firmware = NULL;
> }
>
> - if (wilc && (wilc->vif[0]->ndev || wilc->vif[1]->ndev)) {
> + if (wilc->vif[0]->ndev || wilc->vif[1]->ndev) {
> for (i = 0; i < NUM_CONCURRENT_IFC; i++)
> if (wilc->vif[i]->ndev)
> if (wilc->vif[i]->mac_opened)
>
