[PATCH v2] staging: rtl8723bs: fix potential memory leak in _rtw_init_xmit_priv()

[xkernel . wang]

From: Xiaoke Wang <xkernel.wang@xxxxxxxxxxx>

In _rtw_init_xmit_priv(), there are seven error paths for allocation  
failures without releasing the resources but directly goto `exit`, while   
the exit section only executes `return res;`, which leads to various 
memory leaks.

To properly release them, this patch unifies the error handlers of 
_rtw_init_xmit_priv() and several error handling paths are added.
According to the allocation sequence, each error will jump to its 
corresponding error handling tag.

Signed-off-by: Xiaoke Wang <xkernel.wang@xxxxxxxxxxx>
---
ChangeLog:
v1->v2 update the description.
 drivers/staging/rtl8723bs/core/rtw_xmit.c | 50 +++++++++++++++++------
 1 file changed, 37 insertions(+), 13 deletions(-)

diff --git a/drivers/staging/rtl8723bs/core/rtw_xmit.c b/drivers/staging/rtl8723bs/core/rtw_xmit.c
index 528f920..b288b04 100644
--- a/drivers/staging/rtl8723bs/core/rtw_xmit.c
+++ b/drivers/staging/rtl8723bs/core/rtw_xmit.c
@@ -112,7 +112,7 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	if (!pxmitpriv->pallocated_xmitbuf) {
 		res = _FAIL;
-		goto exit;
+		goto free_frame_buf;
 	}
 
 	pxmitpriv->pxmitbuf = (u8 *)N_BYTE_ALIGMENT((SIZE_PTR)(pxmitpriv->pallocated_xmitbuf), 4);
@@ -132,7 +132,7 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 			msleep(10);
 			res = rtw_os_xmit_resource_alloc(padapter, pxmitbuf, (MAX_XMITBUF_SZ + XMITBUF_ALIGN_SZ), true);
 			if (res == _FAIL)
-				goto exit;
+				goto free_xmitbuf;
 		}
 
 		pxmitbuf->phead = pxmitbuf->pbuf;
@@ -162,7 +162,7 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 	if (!pxmitpriv->xframe_ext_alloc_addr) {
 		pxmitpriv->xframe_ext = NULL;
 		res = _FAIL;
-		goto exit;
+		goto free_xmitbuf;
 	}
 	pxmitpriv->xframe_ext = (u8 *)N_BYTE_ALIGMENT((SIZE_PTR)(pxmitpriv->xframe_ext_alloc_addr), 4);
 	pxframe = (struct xmit_frame *)pxmitpriv->xframe_ext;
@@ -195,7 +195,7 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	if (!pxmitpriv->pallocated_xmit_extbuf) {
 		res = _FAIL;
-		goto exit;
+		goto free_xframe_ext;
 	}
 
 	pxmitpriv->pxmit_extbuf = (u8 *)N_BYTE_ALIGMENT((SIZE_PTR)(pxmitpriv->pallocated_xmit_extbuf), 4);
@@ -210,10 +210,8 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 		pxmitbuf->buf_tag = XMITBUF_MGNT;
 
 		res = rtw_os_xmit_resource_alloc(padapter, pxmitbuf, MAX_XMIT_EXTBUF_SZ + XMITBUF_ALIGN_SZ, true);
-		if (res == _FAIL) {
-			res = _FAIL;
-			goto exit;
-		}
+		if (res == _FAIL)
+			goto free_xmit_extbuf;
 
 		pxmitbuf->phead = pxmitbuf->pbuf;
 		pxmitbuf->pend = pxmitbuf->pbuf + MAX_XMIT_EXTBUF_SZ;
@@ -240,10 +238,8 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 			pxmitbuf->buf_tag = XMITBUF_CMD;
 
 			res = rtw_os_xmit_resource_alloc(padapter, pxmitbuf, MAX_CMDBUF_SZ+XMITBUF_ALIGN_SZ, true);
-			if (res == _FAIL) {
-				res = _FAIL;
-				goto exit;
-			}
+			if (res == _FAIL)
+				goto free_cmd_xmitbuf;
 
 			pxmitbuf->phead = pxmitbuf->pbuf;
 			pxmitbuf->pend = pxmitbuf->pbuf + MAX_CMDBUF_SZ;
@@ -255,7 +251,7 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	res = rtw_alloc_hwxmits(padapter);
 	if (res == _FAIL)
-		goto exit;
+		goto free_cmd_xmitbuf;
 	rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry);
 
 	for (i = 0; i < 4; i++)
@@ -267,6 +263,34 @@ s32 _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	rtw_hal_init_xmit_priv(padapter);
 
+	return res;
+
+free_cmd_xmitbuf:
+	while (i-- > 0) {
+		pxmitbuf = &pxmitpriv->pcmd_xmitbuf[i];
+		if (pxmitbuf)
+			rtw_os_xmit_resource_free(padapter, pxmitbuf, MAX_CMDBUF_SZ + XMITBUF_ALIGN_SZ, true);
+	}
+	i = NR_XMIT_EXTBUFF;
+free_xmit_extbuf:
+	pxmitbuf = (struct xmit_buf *)pxmitpriv->pxmit_extbuf;
+	while (i-- > 0) {
+		rtw_os_xmit_resource_free(padapter, pxmitbuf, (MAX_XMIT_EXTBUF_SZ + XMITBUF_ALIGN_SZ), true);
+		pxmitbuf++;
+	}
+	vfree(pxmitpriv->pallocated_xmit_extbuf);
+free_xframe_ext:
+	vfree(pxmitpriv->xframe_ext_alloc_addr);
+	i = NR_XMITBUFF;
+free_xmitbuf:
+	pxmitbuf = (struct xmit_buf *)pxmitpriv->pxmitbuf;
+	while (i-- > 0) {
+		rtw_os_xmit_resource_free(padapter, pxmitbuf, (MAX_XMITBUF_SZ + XMITBUF_ALIGN_SZ), true);
+		pxmitbuf++;
+	}
+	vfree(pxmitpriv->pallocated_xmitbuf);
+free_frame_buf:
+	vfree(pxmitpriv->pallocated_frame_buf);
 exit:
 	return res;
 }
--