mac80211: allow same PN for AMSDU sub-frames
Some hardware (iwlwifi an example) de-aggregate AMSDUs and copy the IV
as is to the generated MPDUs, so the same PN appears in multiple
packets without being a replay attack. Allow driver to explicitly
indicate that a frame is allowed to have the same PN as the previous
frame.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 07ef937..ce2f6e3 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1068,6 +1068,9 @@
* @RX_FLAG_RADIOTAP_VENDOR_DATA: This frame contains vendor-specific
* radiotap data in the skb->data (before the frame) as described by
* the &struct ieee80211_vendor_radiotap.
+ * @RX_FLAG_ALLOW_SAME_PN: Allow the same PN as same packet before.
+ * This is used for AMSDU subframes which can have the same PN as
+ * the first subframe.
*/
enum mac80211_rx_flags {
RX_FLAG_MMIC_ERROR = BIT(0),
@@ -1101,7 +1104,8 @@
RX_FLAG_5MHZ = BIT(29),
RX_FLAG_AMSDU_MORE = BIT(30),
RX_FLAG_RADIOTAP_VENDOR_DATA = BIT(31),
- RX_FLAG_MIC_STRIPPED = BIT_ULL(32),
+ RX_FLAG_MIC_STRIPPED = BIT_ULL(32),
+ RX_FLAG_ALLOW_SAME_PN = BIT_ULL(33),
};
#define RX_FLAG_STBC_SHIFT 26
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 7e4f265..b48c1e1 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -519,12 +519,16 @@
return RX_DROP_UNUSABLE;
if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
+ int res;
+
ccmp_hdr2pn(pn, skb->data + hdrlen);
queue = rx->security_idx;
- if (memcmp(pn, key->u.ccmp.rx_pn[queue],
- IEEE80211_CCMP_PN_LEN) <= 0) {
+ res = memcmp(pn, key->u.ccmp.rx_pn[queue],
+ IEEE80211_CCMP_PN_LEN);
+ if (res < 0 ||
+ (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
key->u.ccmp.replays++;
return RX_DROP_UNUSABLE;
}
@@ -745,12 +749,16 @@
return RX_DROP_UNUSABLE;
if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
+ int res;
+
gcmp_hdr2pn(pn, skb->data + hdrlen);
queue = rx->security_idx;
- if (memcmp(pn, key->u.gcmp.rx_pn[queue],
- IEEE80211_GCMP_PN_LEN) <= 0) {
+ res = memcmp(pn, key->u.gcmp.rx_pn[queue],
+ IEEE80211_GCMP_PN_LEN);
+ if (res < 0 ||
+ (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
key->u.gcmp.replays++;
return RX_DROP_UNUSABLE;
}