ath9k: fix decrypt_error initialization in ath_rx_tasklet()

commit e1352fde5682ab1bdd2a9e5d75c22d1fe210ef77 upstream.

ath_rx_tasklet() calls ath9k_rx_skb_preprocess() and ath9k_rx_skb_postprocess()
in a loop over the received frames. The decrypt_error flag is
initialized to false
just outside ath_rx_tasklet() loop. ath9k_rx_accept(), called by
ath9k_rx_skb_preprocess(),
only sets decrypt_error to true and never to false.
Then ath_rx_tasklet() calls ath9k_rx_skb_postprocess() and passes
decrypt_error to it.
So, after a decryption error, in ath9k_rx_skb_postprocess(), we can
have a leftover value
from another processed frame. In that case, the frame will not be marked with
RX_FLAG_DECRYPTED even if it is decrypted correctly.
When using CCMP encryption this issue can lead to connection stuck
because of CCMP
PN corruption and a waste of CPU time since mac80211 tries to decrypt an already
deciphered frame with ieee80211_aes_ccm_decrypt.
Fix the issue initializing decrypt_error flag at the begging of the
ath_rx_tasklet() loop.

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index e6d791c..b4cbc82 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -1782,7 +1782,6 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
        struct ieee80211_hw *hw = sc->hw;
        struct ieee80211_hdr *hdr;
        int retval;
-       bool decrypt_error = false;
        struct ath_rx_status rs;
        enum ath9k_rx_qtype qtype;
        bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
@@ -1804,6 +1803,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
        tsf_lower = tsf & 0xffffffff;
 
        do {
+               bool decrypt_error = false;
                /* If handling rx interrupt and flush is in progress => exit */
                if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
                        break;