From ed90542b0ce5415050c6fbfca324bccaafa69f2f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 24 Mar 2012 00:29:46 -0400 Subject: iwlwifi: fix skb truesize underestimation By default, iwlwifi uses order-1 pages (8 KB) to store incoming frames, but doesnt say so in skb->truesize. This makes very possible to exhaust kernel memory since these skb evade normal socket memory accounting. As struct ieee80211_hdr is going to be pulled before calling IP stack, there is no need to use dev_alloc_skb() to reserve NET_SKB_PAD bytes. alloc_skb() is ok in this driver, allowing more tailroom. Pull beginning of frame in skb header, in the hope we can reuse order-1 pages in the driver immediately for small frames and reduce their truesize to the minimum (linear skbs) Signed-off-by: Eric Dumazet Cc: Wey-Yi Guy Cc: "John W. Linville" Cc: Neal Cardwell Signed-off-by: John W. Linville --- drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c') diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c index 8b1a7988e176..aa7aea168138 100644 --- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c +++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c @@ -374,8 +374,9 @@ static void iwl_rx_handle_rxbuf(struct iwl_trans *trans, if (WARN_ON(!rxb)) return; + rxcb.truesize = PAGE_SIZE << hw_params(trans).rx_page_order; dma_unmap_page(trans->dev, rxb->page_dma, - PAGE_SIZE << hw_params(trans).rx_page_order, + rxcb.truesize, DMA_FROM_DEVICE); rxcb._page = rxb->page; -- cgit v1.2.3