2021-08-11 03:14:22

by Tuo Li

Subject: [PATCH] staging: rtl8192e: rtl_core: Fix possible null-pointer dereference in _rtl92e_pci_disconnect()

The variable dev is checked in:
if (dev)

This indicates that it can be NULL. If so, a null-pointer dereference will
occur:
priv = rtllib_priv(dev);

However, the value of priv is not used in the remaining part of this
function. Thus the else-branch can be removed to fix this posible
null-pointer dereference.

Reported-by: TOTE Robot <[email protected]>
Signed-off-by: Tuo Li <[email protected]>
---
drivers/staging/rtl8192e/rtl8192e/rtl_core.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c
index e85d9c2cdc96..0eb37a95b519 100644
--- a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c
+++ b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c
@@ -2557,8 +2557,6 @@ static void _rtl92e_pci_disconnect(struct pci_dev *pdev)
release_mem_region(pci_resource_start(pdev, 1),
pci_resource_len(pdev, 1));
}
- } else {
- priv = rtllib_priv(dev);
}

pci_disable_device(pdev);
--
2.25.1

2021-08-11 07:05:20

by Dan Carpenter

Subject: Re: [PATCH] staging: rtl8192e: rtl_core: Fix possible null-pointer dereference in _rtl92e_pci_disconnect()

On Tue, Aug 10, 2021 at 08:11:35PM -0700, Tuo Li wrote:
> The variable dev is checked in:
> if (dev)
>
> This indicates that it can be NULL. If so, a null-pointer dereference will
> occur:
> priv = rtllib_priv(dev);
>
> However, the value of priv is not used in the remaining part of this
> function. Thus the else-branch can be removed to fix this posible
> null-pointer dereference.
>
> Reported-by: TOTE Robot <[email protected]>
> Signed-off-by: Tuo Li <[email protected]>

Reviewed-by: Dan Carpenter <[email protected]>

Smatch was not smart enough to spot the dereference inside rtllib_priv().
Fortunately, the "dev" variable can't be NULL at this point.

regards,
dan carpenter