[PATCH] staging:rtl8723bs: eliminate usage of skb_clone after skb allocation fail

From: Ivan Safonov
Date: Sat May 02 2020 - 11:14:40 EST


The skb allocated when out of memory
is likely to be discarded during subsequent processing.

Signed-off-by: Ivan Safonov <insafonov@xxxxxxxxx>
---
.../staging/rtl8723bs/hal/rtl8723bs_recv.c | 44 ++++++-------------
drivers/staging/rtl8723bs/os_dep/recv_linux.c | 19 +++-----
2 files changed, 19 insertions(+), 44 deletions(-)

diff --git a/drivers/staging/rtl8723bs/hal/rtl8723bs_recv.c b/drivers/staging/rtl8723bs/hal/rtl8723bs_recv.c
index c3051ebaeb78..29c29e2e125b 100644
--- a/drivers/staging/rtl8723bs/hal/rtl8723bs_recv.c
+++ b/drivers/staging/rtl8723bs/hal/rtl8723bs_recv.c
@@ -311,39 +311,21 @@ static void rtl8723bs_recv_tasklet(unsigned long priv)
}

pkt_copy = rtw_skb_alloc(alloc_sz);
-
- if (pkt_copy) {
- pkt_copy->dev = padapter->pnetdev;
- precvframe->u.hdr.pkt = pkt_copy;
- skb_reserve(pkt_copy, 8 - ((SIZE_PTR)(pkt_copy->data) & 7));/* force pkt_copy->data at 8-byte alignment address */
- skb_reserve(pkt_copy, shift_sz);/* force ip_hdr at 8-byte alignment address according to shift_sz. */
- memcpy(pkt_copy->data, (ptr + rx_report_sz + pattrib->shift_sz), skb_len);
- precvframe->u.hdr.rx_head = pkt_copy->head;
- precvframe->u.hdr.rx_data = precvframe->u.hdr.rx_tail = pkt_copy->data;
- precvframe->u.hdr.rx_end = skb_end_pointer(pkt_copy);
- } else {
- if ((pattrib->mfrag == 1) && (pattrib->frag_num == 0)) {
- DBG_8192C("%s: alloc_skb fail, drop frag frame\n", __func__);
- rtw_free_recvframe(precvframe, &precvpriv->free_recv_queue);
- break;
- }
-
- precvframe->u.hdr.pkt = rtw_skb_clone(precvbuf->pskb);
- if (precvframe->u.hdr.pkt) {
- _pkt *pkt_clone = precvframe->u.hdr.pkt;
-
- pkt_clone->data = ptr + rx_report_sz + pattrib->shift_sz;
- skb_reset_tail_pointer(pkt_clone);
- precvframe->u.hdr.rx_head = precvframe->u.hdr.rx_data = precvframe->u.hdr.rx_tail
- = pkt_clone->data;
- precvframe->u.hdr.rx_end = pkt_clone->data + skb_len;
- } else {
- DBG_8192C("%s: rtw_skb_clone fail\n", __func__);
- rtw_free_recvframe(precvframe, &precvpriv->free_recv_queue);
- break;
- }
+ if (!pkt_copy) {
+ DBG_8192C("%s: alloc_skb fail, drop frame\n", __func__);
+ rtw_free_recvframe(precvframe, &precvpriv->free_recv_queue);
+ break;
}

+ pkt_copy->dev = padapter->pnetdev;
+ precvframe->u.hdr.pkt = pkt_copy;
+ skb_reserve(pkt_copy, 8 - ((SIZE_PTR)(pkt_copy->data) & 7));/* force pkt_copy->data at 8-byte alignment address */
+ skb_reserve(pkt_copy, shift_sz);/* force ip_hdr at 8-byte alignment address according to shift_sz. */
+ memcpy(pkt_copy->data, (ptr + rx_report_sz + pattrib->shift_sz), skb_len);
+ precvframe->u.hdr.rx_head = pkt_copy->head;
+ precvframe->u.hdr.rx_data = precvframe->u.hdr.rx_tail = pkt_copy->data;
+ precvframe->u.hdr.rx_end = skb_end_pointer(pkt_copy);
+
recvframe_put(precvframe, skb_len);
/* recvframe_pull(precvframe, drvinfo_sz + RXDESC_SIZE); */

diff --git a/drivers/staging/rtl8723bs/os_dep/recv_linux.c b/drivers/staging/rtl8723bs/os_dep/recv_linux.c
index 60c35d92ba29..560221723d70 100644
--- a/drivers/staging/rtl8723bs/os_dep/recv_linux.c
+++ b/drivers/staging/rtl8723bs/os_dep/recv_linux.c
@@ -60,21 +60,14 @@ _pkt *rtw_os_alloc_msdu_pkt(union recv_frame *prframe, u16 nSubframe_Length, u8
pattrib = &prframe->u.hdr.attrib;

sub_skb = rtw_skb_alloc(nSubframe_Length + 12);
- if (sub_skb) {
- skb_reserve(sub_skb, 12);
- skb_put_data(sub_skb, (pdata + ETH_HLEN), nSubframe_Length);
- } else {
- sub_skb = rtw_skb_clone(prframe->u.hdr.pkt);
- if (sub_skb) {
- sub_skb->data = pdata + ETH_HLEN;
- sub_skb->len = nSubframe_Length;
- skb_set_tail_pointer(sub_skb, nSubframe_Length);
- } else {
- DBG_871X("%s(): rtw_skb_clone() Fail!!!\n", __func__);
- return NULL;
- }
+ if (!sub_skb) {
+ DBG_871X("%s(): rtw_skb_alloc() Fail!!!\n", __func__);
+ return NULL;
}

+ skb_reserve(sub_skb, 12);
+ skb_put_data(sub_skb, (pdata + ETH_HLEN), nSubframe_Length);
+
eth_type = RTW_GET_BE16(&sub_skb->data[6]);

if (sub_skb->len >= 8 &&
--
2.26.2