From 82a7fc6d4cde3584c8c637d2482994853b44243d Mon Sep 17 00:00:00 2001 From: Larry Finger Date: Wed, 13 Jul 2011 11:06:34 -0500 Subject: [PATCH] staging: rtl8192e: Fix kernel panics due to RX skb allocation failures This driver uses RX skb's of O(2), thus it is possible for memory fragmentation to prevent the allocation of a new one to replace a newly-received buffer. When such a failure occurs, the kernel panics. The fix is to drop an incoming packet whenever such an allocation fails. This fix matches the one done in rtlwifi for other Realtek PCI devices. Signed-off-by: Larry Finger --- drivers/staging/rtl8192e/rtl_core.c | 44 +++++++++++++---------------- 1 file changed, 19 insertions(+), 25 deletions(-) diff --git a/drivers/staging/rtl8192e/rtl_core.c b/drivers/staging/rtl8192e/rtl_core.c index d8504e4d941b..49f787e05503 100644 --- a/drivers/staging/rtl8192e/rtl_core.c +++ b/drivers/staging/rtl8192e/rtl_core.c @@ -2550,12 +2550,18 @@ void rtl8192_rx_normal(struct net_device *dev) rx_desc *pdesc = &priv->rx_ring[rx_queue_idx][priv->rx_idx[rx_queue_idx]]; struct sk_buff *skb = priv->rx_buf[rx_queue_idx][priv->rx_idx[rx_queue_idx]]; - if (pdesc->OWN){ + if (pdesc->OWN) { return; } else { + struct sk_buff *new_skb; - struct sk_buff *new_skb = NULL; - if (!priv->ops->rx_query_status_descriptor(dev, &stats, pdesc, skb)) + if (!priv->ops->rx_query_status_descriptor(dev, &stats, + pdesc, skb)) + goto done; + new_skb = dev_alloc_skb(priv->rxbuffersize); + /* if allocation of new skb failed - drop current packet + * and reuse skb */ + if (unlikely(!new_skb)) goto done; pci_unmap_single(priv->pdev, @@ -2564,24 +2570,24 @@ void rtl8192_rx_normal(struct net_device *dev) PCI_DMA_FROMDEVICE); skb_put(skb, pdesc->Length); - skb_reserve(skb, stats.RxDrvInfoSize + stats.RxBufShift); + skb_reserve(skb, stats.RxDrvInfoSize + + stats.RxBufShift); skb_trim(skb, skb->len - 4/*sCrcLng*/); rtllib_hdr = (struct rtllib_hdr_1addr *)skb->data; - if (is_broadcast_ether_addr(rtllib_hdr->addr1)) { - }else if (is_multicast_ether_addr(rtllib_hdr->addr1)){ - }else { + if (!is_broadcast_ether_addr(rtllib_hdr->addr1) && + !is_multicast_ether_addr(rtllib_hdr->addr1)) { /* unicast packet */ unicast_packet = true; } fc = le16_to_cpu(rtllib_hdr->frame_ctl); type = WLAN_FC_GET_TYPE(fc); if (type == RTLLIB_FTYPE_MGMT) - { bLedBlinking = false; - } + if (bLedBlinking) if (priv->rtllib->LedControlHandler) - priv->rtllib->LedControlHandler(dev, LED_CTL_RX); + priv->rtllib->LedControlHandler(dev, + LED_CTL_RX); if (stats.bCRC) { if (type != RTLLIB_FTYPE_MGMT) @@ -2592,28 +2598,16 @@ void rtl8192_rx_normal(struct net_device *dev) skb_len = skb->len; - if (1) - { if (!rtllib_rx(priv->rtllib, skb, &stats)){ dev_kfree_skb_any(skb); } else { priv->stats.rxok++; - if (unicast_packet) { + if (unicast_packet) priv->stats.rxbytesunicast += skb_len; - } - } - }else{ - dev_kfree_skb_any(skb); } - new_skb = dev_alloc_skb(priv->rxbuffersize); - if (unlikely(!new_skb)) - { - printk("==========>can't alloc skb for rx\n"); - goto done; - } - skb=new_skb; - skb->dev = dev; + skb = new_skb; + skb->dev = dev; priv->rx_buf[rx_queue_idx][priv->rx_idx[rx_queue_idx]] = skb; *((dma_addr_t *) skb->cb) = pci_map_single(priv->pdev, skb_tail_pointer_rsl(skb), priv->rxbuffersize, PCI_DMA_FROMDEVICE); -- 2.20.1