staging: rtl8188eu: Fix potential NULL pointer dereference of kcalloc

hwxmits is allocated via kcalloc and not checked for failure before its
dereference. The patch fixes this problem by returning error upstream
in rtl8723bs, rtl8188eu.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Acked-by: Mukesh Ojha <mojha@codeaurora.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_xmit.c

@@ -174,7 +174,9 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	pxmitpriv->free_xmit_extbuf_cnt = num_xmit_extbuf;
 
-	rtw_alloc_hwxmits(padapter);
+	res = rtw_alloc_hwxmits(padapter);
+	if (res == _FAIL)
+		goto exit;
 	rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry);
 
 	for (i = 0; i < 4; i++)
@@ -1503,7 +1505,7 @@ s32 rtw_xmit_classifier(struct adapter *padapter, struct xmit_frame *pxmitframe)
 	return res;
 }
 
-void rtw_alloc_hwxmits(struct adapter *padapter)
+s32 rtw_alloc_hwxmits(struct adapter *padapter)
 {
 	struct hw_xmit *hwxmits;
 	struct xmit_priv *pxmitpriv = &padapter->xmitpriv;
@@ -1512,6 +1514,8 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
 
 	pxmitpriv->hwxmits = kcalloc(pxmitpriv->hwxmit_entry,
 				     sizeof(struct hw_xmit), GFP_KERNEL);
+	if (!pxmitpriv->hwxmits)
+		return _FAIL;
 
 	hwxmits = pxmitpriv->hwxmits;
 
@@ -1519,6 +1523,7 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
 	hwxmits[1] .sta_queue = &pxmitpriv->vi_pending;
 	hwxmits[2] .sta_queue = &pxmitpriv->be_pending;
 	hwxmits[3] .sta_queue = &pxmitpriv->bk_pending;
+	return _SUCCESS;
 }
 
 void rtw_free_hwxmits(struct adapter *padapter)

drivers/staging/rtl8188eu/include/rtw_xmit.h

@@ -336,7 +336,7 @@ s32 rtw_txframes_sta_ac_pending(struct adapter *padapter,
 void rtw_init_hwxmits(struct hw_xmit *phwxmit, int entry);
 s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter);
 void _rtw_free_xmit_priv(struct xmit_priv *pxmitpriv);
-void rtw_alloc_hwxmits(struct adapter *padapter);
+s32 rtw_alloc_hwxmits(struct adapter *padapter);
 void rtw_free_hwxmits(struct adapter *padapter);
 s32 rtw_xmit(struct adapter *padapter, struct sk_buff **pkt);
 

drivers/staging/rtl8723bs/core/rtw_xmit.c

@@ -260,7 +260,9 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 		}
 	}
 
-	rtw_alloc_hwxmits(padapter);
+	res = rtw_alloc_hwxmits(padapter);
+	if (res == _FAIL)
+		goto exit;
 	rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry);
 
 	for (i = 0; i < 4; i++) {
@@ -2144,7 +2146,7 @@ s32 rtw_xmit_classifier(struct adapter *padapter, struct xmit_frame *pxmitframe)
 	return res;
 }
 
-void rtw_alloc_hwxmits(struct adapter *padapter)
+s32 rtw_alloc_hwxmits(struct adapter *padapter)
 {
 	struct hw_xmit *hwxmits;
 	struct xmit_priv *pxmitpriv = &padapter->xmitpriv;
@@ -2155,10 +2157,8 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
 
 	pxmitpriv->hwxmits = rtw_zmalloc(sizeof(struct hw_xmit) * pxmitpriv->hwxmit_entry);
 
-	if (pxmitpriv->hwxmits == NULL) {
-		DBG_871X("alloc hwxmits fail!...\n");
-		return;
-	}
+	if (!pxmitpriv->hwxmits)
+		return _FAIL;
 
 	hwxmits = pxmitpriv->hwxmits;
 
@@ -2204,7 +2204,7 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
 
 	}
 
-
+	return _SUCCESS;
 }
 
 void rtw_free_hwxmits(struct adapter *padapter)

drivers/staging/rtl8723bs/include/rtw_xmit.h

@@ -487,7 +487,7 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter);
 void _rtw_free_xmit_priv (struct xmit_priv *pxmitpriv);
 
 
-void rtw_alloc_hwxmits(struct adapter *padapter);
+s32 rtw_alloc_hwxmits(struct adapter *padapter);
 void rtw_free_hwxmits(struct adapter *padapter);