diff options
author | Larry Finger <Larry.Finger@lwfinger.net> | 2014-12-30 21:33:07 -0600 |
---|---|---|
committer | Kalle Valo <kvalo@codeaurora.org> | 2015-01-05 10:05:44 +0200 |
commit | e9538cf4f90713eca71b1d6a74b4eae1d445c664 (patch) | |
tree | f3c3eff86b136edf1890099ffc184b61db05fd4c /drivers/net/wireless/rtlwifi/pci.c | |
parent | 7ce67a38f799d1fb332f672b117efbadedaa5352 (diff) | |
download | linux-e9538cf4f90713eca71b1d6a74b4eae1d445c664.tar.bz2 |
rtlwifi: Fix error when accessing unmapped memory in skb
These drivers use 9100-byte receive buffers, thus allocating an skb requires
an O(3) memory allocation. Under heavy memory loads and fragmentation, such
a request can fail. Previous versions of the driver have dropped the packet
and reused the old buffer; however, the new version introduced a bug in that
it released the old buffer before trying to allocate a new one. The previous
method is implemented here. The skb is unmapped before any attempt is made to
allocate another.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org> [v3.18]
Reported-by: Eric Biggers <ebiggers3@gmail.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Diffstat (limited to 'drivers/net/wireless/rtlwifi/pci.c')
-rw-r--r-- | drivers/net/wireless/rtlwifi/pci.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c index 846a2e6e34d8..c70efb9a6e78 100644 --- a/drivers/net/wireless/rtlwifi/pci.c +++ b/drivers/net/wireless/rtlwifi/pci.c @@ -666,7 +666,8 @@ tx_status_ok: } static int _rtl_pci_init_one_rxdesc(struct ieee80211_hw *hw, - u8 *entry, int rxring_idx, int desc_idx) + struct sk_buff *new_skb, u8 *entry, + int rxring_idx, int desc_idx) { struct rtl_priv *rtlpriv = rtl_priv(hw); struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw)); @@ -674,11 +675,15 @@ static int _rtl_pci_init_one_rxdesc(struct ieee80211_hw *hw, u8 tmp_one = 1; struct sk_buff *skb; + if (likely(new_skb)) { + skb = new_skb; + goto remap; + } skb = dev_alloc_skb(rtlpci->rxbuffersize); if (!skb) return 0; - rtlpci->rx_ring[rxring_idx].rx_buf[desc_idx] = skb; +remap: /* just set skb->cb to mapping addr for pci_unmap_single use */ *((dma_addr_t *)skb->cb) = pci_map_single(rtlpci->pdev, skb_tail_pointer(skb), @@ -686,6 +691,7 @@ static int _rtl_pci_init_one_rxdesc(struct ieee80211_hw *hw, bufferaddress = *((dma_addr_t *)skb->cb); if (pci_dma_mapping_error(rtlpci->pdev, bufferaddress)) return 0; + rtlpci->rx_ring[rxring_idx].rx_buf[desc_idx] = skb; if (rtlpriv->use_new_trx_flow) { rtlpriv->cfg->ops->set_desc(hw, (u8 *)entry, false, HW_DESC_RX_PREPARE, @@ -781,6 +787,7 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw) /*rx pkt */ struct sk_buff *skb = rtlpci->rx_ring[rxring_idx].rx_buf[ rtlpci->rx_ring[rxring_idx].idx]; + struct sk_buff *new_skb; if (rtlpriv->use_new_trx_flow) { rx_remained_cnt = @@ -807,6 +814,13 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw) pci_unmap_single(rtlpci->pdev, *((dma_addr_t *)skb->cb), rtlpci->rxbuffersize, PCI_DMA_FROMDEVICE); + /* get a new skb - if fail, old one will be reused */ + new_skb = dev_alloc_skb(rtlpci->rxbuffersize); + if (unlikely(!new_skb)) { + pr_err("Allocation of new skb failed in %s\n", + __func__); + goto no_new; + } if (rtlpriv->use_new_trx_flow) { buffer_desc = &rtlpci->rx_ring[rxring_idx].buffer_desc @@ -911,14 +925,16 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw) schedule_work(&rtlpriv->works.lps_change_work); } end: + skb = new_skb; +no_new: if (rtlpriv->use_new_trx_flow) { - _rtl_pci_init_one_rxdesc(hw, (u8 *)buffer_desc, + _rtl_pci_init_one_rxdesc(hw, skb, (u8 *)buffer_desc, rxring_idx, - rtlpci->rx_ring[rxring_idx].idx); + rtlpci->rx_ring[rxring_idx].idx); } else { - _rtl_pci_init_one_rxdesc(hw, (u8 *)pdesc, rxring_idx, + _rtl_pci_init_one_rxdesc(hw, skb, (u8 *)pdesc, + rxring_idx, rtlpci->rx_ring[rxring_idx].idx); - if (rtlpci->rx_ring[rxring_idx].idx == rtlpci->rxringcount - 1) rtlpriv->cfg->ops->set_desc(hw, (u8 *)pdesc, @@ -1307,7 +1323,7 @@ static int _rtl_pci_init_rx_ring(struct ieee80211_hw *hw, int rxring_idx) rtlpci->rx_ring[rxring_idx].idx = 0; for (i = 0; i < rtlpci->rxringcount; i++) { entry = &rtlpci->rx_ring[rxring_idx].buffer_desc[i]; - if (!_rtl_pci_init_one_rxdesc(hw, (u8 *)entry, + if (!_rtl_pci_init_one_rxdesc(hw, NULL, (u8 *)entry, rxring_idx, i)) return -ENOMEM; } @@ -1332,7 +1348,7 @@ static int _rtl_pci_init_rx_ring(struct ieee80211_hw *hw, int rxring_idx) for (i = 0; i < rtlpci->rxringcount; i++) { entry = &rtlpci->rx_ring[rxring_idx].desc[i]; - if (!_rtl_pci_init_one_rxdesc(hw, (u8 *)entry, + if (!_rtl_pci_init_one_rxdesc(hw, NULL, (u8 *)entry, rxring_idx, i)) return -ENOMEM; } |