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From:   Ivan Safonov <insafonov@gmail.com>
To:     Larry Finger <Larry.Finger@lwfinger.net>
Cc:     Florian Schilhabel <florian.c.schilhabel@googlemail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Nishka Dasgupta <nishkadg.linux@gmail.com>,
        Cristiane Naves <cristianenavescardoso09@gmail.com>,
        Wambui Karuga <wambui.karugax@gmail.com>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Merwin Trever Ferrao <merwintf@gmail.com>,
        Kees Cook <keescook@chromium.org>,
        Michael Straube <straube.linux@gmail.com>,
        devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
        Ivan Safonov <insafonov@gmail.com>
Subject: [PATCH] staging:rtl8712: avoid skb_clone after skb allocation fail
Date:   Sun, 31 May 2020 14:05:47 +0300
Message-Id: <20200531110548.9318-1-insafonov@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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The skb allocated when out of memory is likely to be discarded
during subsequent processing.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
---
 drivers/staging/rtl8712/rtl8712_recv.c | 29 ++++++++++----------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/drivers/staging/rtl8712/rtl8712_recv.c b/drivers/staging/rtl8712/rtl8712_recv.c
index 116773943a2e..570030be3077 100644
--- a/drivers/staging/rtl8712/rtl8712_recv.c
+++ b/drivers/staging/rtl8712/rtl8712_recv.c
@@ -1037,24 +1037,17 @@ static void recvbuf2recvframe(struct _adapter *padapter, struct sk_buff *pskb)
 		 */
 		alloc_sz += 6;
 		pkt_copy = netdev_alloc_skb(padapter->pnetdev, alloc_sz);
-		if (pkt_copy) {
-			precvframe->u.hdr.pkt = pkt_copy;
-			skb_reserve(pkt_copy, 4 - ((addr_t)(pkt_copy->data)
-				    % 4));
-			skb_reserve(pkt_copy, shift_sz);
-			memcpy(pkt_copy->data, pbuf, tmp_len);
-			precvframe->u.hdr.rx_head = precvframe->u.hdr.rx_data =
-				 precvframe->u.hdr.rx_tail = pkt_copy->data;
-			precvframe->u.hdr.rx_end = pkt_copy->data + alloc_sz;
-		} else {
-			precvframe->u.hdr.pkt = skb_clone(pskb, GFP_ATOMIC);
-			if (!precvframe->u.hdr.pkt)
-				return;
-			precvframe->u.hdr.rx_head = pbuf;
-			precvframe->u.hdr.rx_data = pbuf;
-			precvframe->u.hdr.rx_tail = pbuf;
-			precvframe->u.hdr.rx_end = pbuf + alloc_sz;
-		}
+		if (!pkt_copy)
+			return;
+
+		precvframe->u.hdr.pkt = pkt_copy;
+		skb_reserve(pkt_copy, 4 - ((addr_t)(pkt_copy->data) % 4));
+		skb_reserve(pkt_copy, shift_sz);
+		memcpy(pkt_copy->data, pbuf, tmp_len);
+		precvframe->u.hdr.rx_head = precvframe->u.hdr.rx_data =
+			precvframe->u.hdr.rx_tail = pkt_copy->data;
+		precvframe->u.hdr.rx_end = pkt_copy->data + alloc_sz;
+
 		recvframe_put(precvframe, tmp_len);
 		recvframe_pull(precvframe, drvinfo_sz + RXDESC_SIZE);
 		/* because the endian issue, driver avoid reference to the
-- 
2.26.2