On Sat, 2009-11-28 at 15:47 +0100, Benoit Papillault wrote: > From: Benoit PAPILLAULT <benoit.papillault@xxxxxxx> > > ieee80211_verify_alignment has been improved to avoid small 802.11 frame (<2 > bytes) and skip checking for data alignment when there is no 802.11 data (when > the frame length is less or egal to the header length) None of this is necessary. > --- a/net/mac80211/rx.c > +++ b/net/mac80211/rx.c > @@ -386,10 +386,23 @@ static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx) > "unaligned packet at 0x%p\n", rx->skb->data)) > return; > > + /* before using the hdr->frame_control field, we need to check that > + * skb contains at least 2 bytes */ > + > + if (rx->skb->len < 2) > + return ; > + Frames shorter than 16 bytes never reach this point. > if (!ieee80211_is_data_present(hdr->frame_control)) > return; > > hdrlen = ieee80211_hdrlen(hdr->frame_control); > + > + /* before checking data alignment, we need to check that skb contains > + * at least 1 byte of data */ > + > + if (rx->skb->len <= hdrlen) > + return; > + Even if this could happen it's not true -- we do not need a byte of data to verify that it's aligned properly. After all, even the empty string can be aligned -- we never actually dereference the data there. johannes
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