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>
This commit is contained in:
Johannes Berg 2018-12-15 11:03:12 +02:00
parent dc7eb0f2c2
commit efc38dd7d5

View file

@ -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 */