Re: [PATCH 3/3] staging: r8188eu: fix null check in _rtw_free_mlme_priv

From: Pavel Skripkin
Date: Sun Apr 24 2022 - 15:00:21 EST


Hi Vihas,

On 4/24/22 19:31, Vihas Makwana wrote:
There's a NULL check on pmlmepriv in rtw_mlme.c:112 which makes no sense
as rtw_free_mlme_priv_ie_data() dereferences it unconditionally and it
would have already crashed at this point.
Fix this by moving rtw_free_mlme_priv_ie_data() inside the check.

Signed-off-by: Vihas Makwana <makvihas@xxxxxxxxx>

That's good catch, but looks like the check is just redundant

This function is called only from it's wrapper called rtw_free_mlme_priv() and rtw_free_mlme_priv() is called from 2 places:

4 drivers/staging/r8188eu/os_dep/os_intfs.c|531 col 2| rtw_free_mlme_priv(&padapter->mlmepriv);
5 drivers/staging/r8188eu/os_dep/os_intfs.c|579 col 2| rtw_free_mlme_priv(&padapter->mlmepriv);

_Very_ unlikely that `&padapter->mlmepriv` expression will become NULL.


---
drivers/staging/r8188eu/core/rtw_mlme.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_mlme.c b/drivers/staging/r8188eu/core/rtw_mlme.c
index 081c02417..87c754462 100644
--- a/drivers/staging/r8188eu/core/rtw_mlme.c
+++ b/drivers/staging/r8188eu/core/rtw_mlme.c
@@ -109,12 +109,10 @@ void rtw_free_mlme_priv_ie_data(struct mlme_priv *pmlmepriv)
void _rtw_free_mlme_priv(struct mlme_priv *pmlmepriv)
{
-
- rtw_free_mlme_priv_ie_data(pmlmepriv);
-
- if (pmlmepriv)
+ if (pmlmepriv) {
+ rtw_free_mlme_priv_ie_data(pmlmepriv);
vfree(pmlmepriv->free_bss_buf);
-
+ }
}
struct wlan_network *_rtw_alloc_network(struct mlme_priv *pmlmepriv)/* _queue *free_queue) */




With regards,
Pavel Skripkin