Commit efc38dd7 authored Dec 15, 2018 by Johannes Berg

mac80211: fix radiotap vendor presence bitmap handling



Due to the alignment handling, it actually matters where in the code
we add the 4 bytes for the presence bitmap to the length; the first
field is the timestamp with 8 byte alignment so we need to add the
space for the extra vendor namespace presence bitmap *before* we do
any alignment for the fields.

Move the presence bitmap length accounting to the right place to fix
the alignment for the data properly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

parent dc7eb0f2

net/mac80211/rx.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -143,6 +143,9 @@ ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local,
		/* allocate extra bitmaps */
		if (status->chains)
		len += 4 * hweight8(status->chains);
		/* vendor presence bitmap */
		if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA)
		len += 4;

		if (ieee80211_have_rx_timestamp(status)) {
		len = ALIGN(len, 8);
		@@ -207,8 +210,6 @@ ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local,
		if (status->flag & RX_FLAG_RADIOTAP_VENDOR_DATA) {
		struct ieee80211_vendor_radiotap rtap = (void )skb->data;

		/* vendor presence bitmap */
		len += 4;
		/* alignment for fixed 6-byte vendor data header */
		len = ALIGN(len, 2);
		/* vendor data header */