From a26cbc650846b74dd7f46dd877fd30c472df14a1 Mon Sep 17 00:00:00 2001 From: Gertjan van Wingerde Date: Fri, 6 Jun 2008 22:54:28 +0200 Subject: rt2x00: Fix double usage of skb->cb in USB RX path. It is not safe to use the skb->cb area for both the rxd and skb_frame_desc data at the same time, while they occupy an overlapping piece of memory. This can lead to hard to trace crashes as pointers within skb_frame_desc are pointing into nowhere, or the rxd data is overwritten with non-sense. Fix it by copying the rxd to a small buffer on the stack. Signed-off-by: Gertjan van Wingerde Signed-off-by: Ivo van Doorn Signed-off-by: John W. Linville --- drivers/net/wireless/rt2x00/rt73usb.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) (limited to 'drivers/net/wireless/rt2x00/rt73usb.c') diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c index 800a1e278d1e..505a9f5e09e9 100644 --- a/drivers/net/wireless/rt2x00/rt73usb.c +++ b/drivers/net/wireless/rt2x00/rt73usb.c @@ -1428,14 +1428,10 @@ static void rt73usb_fill_rxdone(struct queue_entry *entry, u32 word1; /* - * Copy descriptor to the skb->cb array, this has 2 benefits: - * 1) Each descriptor word is 4 byte aligned. - * 2) Descriptor is safe from moving of frame data in rt2x00usb. + * Copy descriptor to the skbdesc->desc buffer, making it safe from moving of + * frame data in rt2x00usb. */ - skbdesc->desc_len = - min_t(u16, entry->queue->desc_size, sizeof(entry->skb->cb)); - memcpy(entry->skb->cb, rxd, skbdesc->desc_len); - skbdesc->desc = entry->skb->cb; + memcpy(skbdesc->desc, rxd, skbdesc->desc_len); rxd = (__le32 *)skbdesc->desc; /* -- cgit v1.2.2