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From:   Aditya Pakki <pakki001@umn.edu>
To:     pakki001@umn.edu
Cc:     kjlu@umn.edu, Larry Finger <Larry.Finger@lwfinger.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Michael Straube <straube.linux@gmail.com>,
        Colin Ian King <colin.king@canonical.com>,
        Hardik Singh Rathore <hardiksingh.k@gmail.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Nathan Chancellor <natechancellor@gmail.com>,
        Hans de Goede <hdegoede@redhat.com>,
        devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] staging: rtl8188eu: Fix potential NULL pointer dereference
Date:   Tue, 19 Mar 2019 16:07:54 -0500
Message-Id: <20190319210801.19074-1-pakki001@umn.edu>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

hwxmits is allocated via kcalloc and not checked for failure before its
dereference. The patch fixes this problem by returning an error in
rtl8723bs.

---
v1: Return error and remove print in case of failure, per Greg
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
---
 drivers/staging/rtl8188eu/core/rtw_xmit.c    | 10 ++++++++--
 drivers/staging/rtl8188eu/include/rtw_xmit.h |  2 +-
 drivers/staging/rtl8723bs/core/rtw_xmit.c    | 14 +++++++-------
 drivers/staging/rtl8723bs/include/rtw_xmit.h |  2 +-
 4 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_xmit.c b/drivers/staging/rtl8188eu/core/rtw_xmit.c
index 1723a47a96b4..b70a87bda6f8 100644
--- a/drivers/staging/rtl8188eu/core/rtw_xmit.c
+++ b/drivers/staging/rtl8188eu/core/rtw_xmit.c
@@ -174,7 +174,10 @@ 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 +1506,7 @@ 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 +1515,8 @@ 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 +1524,7 @@ 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)
diff --git a/drivers/staging/rtl8188eu/include/rtw_xmit.h b/drivers/staging/rtl8188eu/include/rtw_xmit.h
index 788f59c74ea1..ba7e15fbde72 100644
--- a/drivers/staging/rtl8188eu/include/rtw_xmit.h
+++ b/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);
 
diff --git a/drivers/staging/rtl8723bs/core/rtw_xmit.c b/drivers/staging/rtl8723bs/core/rtw_xmit.c
index 094d61bcb469..b87f13a0b563 100644
--- a/drivers/staging/rtl8723bs/core/rtw_xmit.c
+++ b/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)
diff --git a/drivers/staging/rtl8723bs/include/rtw_xmit.h b/drivers/staging/rtl8723bs/include/rtw_xmit.h
index 1b38b9182b31..37f42b2f22f1 100644
--- a/drivers/staging/rtl8723bs/include/rtw_xmit.h
+++ b/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);
 
 
-- 
2.17.1