From f5300e04df78feae8107c1846dd3a9e27c071b2f Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Mon, 18 Jan 2010 00:07:38 +0100 Subject: [PATCH] p54pci: rx frame length check A long time ago, a user reported several crashes due to data corruptions which are likely the result of a not-100%-supported, or faulty? PCI bridge. ( http://patchwork.kernel.org/patch/53004/ ) This patch fixes entry #1. "1. p54p_check_rx_ring - skb_over_panic: Under a ping flood or just left running for a bit would panic with a skb_over_panic." As described in the mail: The invalid frame length causes skb_put to bailout and trigger a crash. Note: Simply dropping the frame is problematic, because if its content contains a tx feedback we would lose some portion of the device memory space.... And the driver/mac80211 should handle all other invalid data. Reported-by: Quintin Pitts Signed-off-by: Christian Lamparter Signed-off-by: John W. Linville --- drivers/net/wireless/p54/p54pci.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/net/wireless/p54/p54pci.c b/drivers/net/wireless/p54/p54pci.c index a15962a..a72f7c2 100644 --- a/drivers/net/wireless/p54/p54pci.c +++ b/drivers/net/wireless/p54/p54pci.c @@ -197,6 +197,14 @@ static void p54p_check_rx_ring(struct ieee80211_hw *dev, u32 *index, i %= ring_limit; continue; } + + if (unlikely(len > priv->common.rx_mtu)) { + if (net_ratelimit()) + dev_err(&priv->pdev->dev, "rx'd frame size " + "exceeds length threshold.\n"); + + len = priv->common.rx_mtu; + } skb_put(skb, len); if (p54_rx(dev, skb)) { -- 1.8.2.3