[PATCH v3 1/2] staging: r8188eu: fix potential memory leak in _rtw_init_xmit_priv()

[PATCH v3 1/2] staging: r8188eu: fix potential memory leak in _rtw_init_xmit_priv()

[xkernel.wang]

From: Xiaoke Wang <xkernel.wang@foxmail.com>

In _rtw_init_xmit_priv(), there are several error paths for allocation
failures just jump to the `exit` section. However, there is no action
will be performed, so the allocated resources are not properly released,
which leads to various memory leaks.

To properly release them, this patch unifies the error handling code and
several error handling paths are added.
According to the allocation sequence, if the validation fails, it will
jump to its corresponding error tag to release the resources.

Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
---
ChangeLog:
v1->v2 update the description and adjust the sequence of patches.
v2->v3 None to this patch, but some to another pathch in this series.
 drivers/staging/r8188eu/core/rtw_xmit.c | 32 ++++++++++++++++++-------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
index aede8ef..865b2fc 100644
--- a/drivers/staging/r8188eu/core/rtw_xmit.c
+++ b/drivers/staging/r8188eu/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_t)(pxmitpriv->pallocated_xmitbuf), 4);
@@ -134,7 +134,7 @@ 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));
 			if (res == _FAIL)
-				goto exit;
+				goto free_xmitbuf;
 		}
 
 		pxmitbuf->flags = XMIT_VO_QUEUE;
@@ -152,7 +152,7 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	if (!pxmitpriv->pallocated_xmit_extbuf) {
 		res = _FAIL;
-		goto exit;
+		goto free_xmitbuf;
 	}
 
 	pxmitpriv->pxmit_extbuf = (u8 *)N_BYTE_ALIGMENT((size_t)(pxmitpriv->pallocated_xmit_extbuf), 4);
@@ -167,10 +167,8 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 		pxmitbuf->ext_tag = true;
 
 		res = rtw_os_xmit_resource_alloc(padapter, pxmitbuf, max_xmit_extbuf_size + XMITBUF_ALIGN_SZ);
-		if (res == _FAIL) {
-			res = _FAIL;
-			goto exit;
-		}
+		if (res == _FAIL)
+			goto free_xmit_extbuf;
 
 		list_add_tail(&pxmitbuf->list, &pxmitpriv->free_xmit_extbuf_queue.queue);
 		pxmitbuf++;
@@ -200,8 +198,26 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	rtl8188eu_init_xmit_priv(padapter);
 
-exit:
+	return _SUCCESS;
 
+free_xmit_extbuf:
+	pxmitbuf = (struct xmit_buf *)pxmitpriv->pxmit_extbuf;
+	while (i-- > 0) {
+		rtw_os_xmit_resource_free(padapter, pxmitbuf, (max_xmit_extbuf_size + XMITBUF_ALIGN_SZ));
+		pxmitbuf++;
+	}
+	vfree(pxmitpriv->pallocated_xmit_extbuf);
+	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));
+		pxmitbuf++;
+	}
+	vfree(pxmitpriv->pallocated_xmitbuf);
+free_frame_buf:
+	vfree(pxmitpriv->pallocated_frame_buf);
+exit:
 	return res;
 }
 
-- 

[PATCH v3 2/2] staging: r8188eu: check the return of kzalloc()

[xkernel.wang]

From: Xiaoke Wang <xkernel.wang@foxmail.com>

kzalloc() is a memory allocation function which can return NULL when
some internal memory errors happen. So it is better to handle the return
of it to prevent potential wrong memory access.

Besides, to propagate the error to the caller, the type of
rtw_alloc_hwxmits() is changed to `int` and another check is added to 
its caller.
Then if kzalloc() fails, the caller will properly jump to the
corresponding error hanlding code.

Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
---
ChangeLog:
v1->v2 update the description and adjust the sequence of patches.
v2->v3 change `s32` -> `int`.
 drivers/staging/r8188eu/core/rtw_xmit.c    | 10 ++++++++--
 drivers/staging/r8188eu/include/rtw_xmit.h |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
index 865b2fc..92a1ad3 100644
--- a/drivers/staging/r8188eu/core/rtw_xmit.c
+++ b/drivers/staging/r8188eu/core/rtw_xmit.c
@@ -176,7 +176,9 @@ 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 free_xmit_extbuf;
 	rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry);
 
 	for (i = 0; i < 4; i++)
@@ -1490,7 +1492,7 @@ s32 rtw_xmit_classifier(struct adapter *padapter, struct xmit_frame *pxmitframe)
 	return res;
 }
 
-void rtw_alloc_hwxmits(struct adapter *padapter)
+int rtw_alloc_hwxmits(struct adapter *padapter)
 {
 	struct hw_xmit *hwxmits;
 	struct xmit_priv *pxmitpriv = &padapter->xmitpriv;
@@ -1498,6 +1500,8 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
 	pxmitpriv->hwxmit_entry = HWXMIT_ENTRY;
 
 	pxmitpriv->hwxmits = kzalloc(sizeof(struct hw_xmit) * pxmitpriv->hwxmit_entry, GFP_KERNEL);
+	if (!pxmitpriv->hwxmits)
+		return _FAIL;
 
 	hwxmits = pxmitpriv->hwxmits;
 
@@ -1514,6 +1518,8 @@ void rtw_alloc_hwxmits(struct adapter *padapter)
 		hwxmits[3] .sta_queue = &pxmitpriv->bk_pending;
 	} else {
 	}
+
+	return _SUCCESS;
 }
 
 void rtw_free_hwxmits(struct adapter *padapter)
diff --git a/drivers/staging/r8188eu/include/rtw_xmit.h b/drivers/staging/r8188eu/include/rtw_xmit.h
index b2df148..fa35776 100644
--- a/drivers/staging/r8188eu/include/rtw_xmit.h
+++ b/drivers/staging/r8188eu/include/rtw_xmit.h
@@ -341,7 +341,7 @@ 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);
+int rtw_alloc_hwxmits(struct adapter *padapter);
 void rtw_free_hwxmits(struct adapter *padapter);
 s32 rtw_xmit(struct adapter *padapter, struct sk_buff **pkt);
 
-- 

Re: [PATCH v3 1/2] staging: r8188eu: fix potential memory leak in _rtw_init_xmit_priv()

[Greg KH]

On Fri, Apr 08, 2022 at 09:37:10AM +0800, xkernel.wang@foxmail.com wrote:
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
> 
> In _rtw_init_xmit_priv(), there are several error paths for allocation
> failures just jump to the `exit` section. However, there is no action
> will be performed, so the allocated resources are not properly released,
> which leads to various memory leaks.
> 
> To properly release them, this patch unifies the error handling code and
> several error handling paths are added.
> According to the allocation sequence, if the validation fails, it will
> jump to its corresponding error tag to release the resources.
> 
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
> ChangeLog:
> v1->v2 update the description and adjust the sequence of patches.
> v2->v3 None to this patch, but some to another pathch in this series.
>  drivers/staging/r8188eu/core/rtw_xmit.c | 32 ++++++++++++++++++-------
>  1 file changed, 24 insertions(+), 8 deletions(-)

I still have 12 patches in my queue from you, yet no idea which order
they belong in at all, nor which is the latest versions :(

Please rebase and resubmit them ALL as a single patch series so I can
have a hint as to what to do here.

thanks,

greg k-h