ath9k: fix spurious MIC failure reports

According to the hardware documentation, the MIC failure bit is only
valid if the frame was decrypted using a valid TKIP key and is not a
fragment.
In some setups I've seen hardware-reported MIC failures on an AP that
was configured for CCMP only, so it's clear that additional checks are
necessary.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath.h b/drivers/net/wireless/ath/ath.h
index d32f282..a706202 100644 (file)
--- a/drivers/net/wireless/ath/ath.h
+++ b/drivers/net/wireless/ath/ath.h
@@ -119,6 +119,7 @@ struct ath_common {
 
        u32 keymax;
        DECLARE_BITMAP(keymap, ATH_KEYMAX);
+       DECLARE_BITMAP(tkip_keymap, ATH_KEYMAX);
        u8 splitmic;
 
        struct ath_regulatory regulatory;

diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless/ath/ath9k/common.c
index 31cfe46..2dab64b 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/common.c
+++ b/drivers/net/wireless/ath/ath9k/common.c
@@ -372,9 +372,13 @@ int ath9k_cmn_key_config(struct ath_common *common,
        set_bit(idx, common->keymap);
        if (key->cipher == WLAN_CIPHER_SUITE_TKIP) {
                set_bit(idx + 64, common->keymap);
+               set_bit(idx, common->tkip_keymap);
+               set_bit(idx + 64, common->tkip_keymap);
                if (common->splitmic) {
                        set_bit(idx + 32, common->keymap);
                        set_bit(idx + 64 + 32, common->keymap);
+                       set_bit(idx + 32, common->tkip_keymap);
+                       set_bit(idx + 64 + 32, common->tkip_keymap);
                }
        }
 
@@ -399,10 +403,17 @@ void ath9k_cmn_key_delete(struct ath_common *common,
                return;
 
        clear_bit(key->hw_key_idx + 64, common->keymap);
+
+       clear_bit(key->hw_key_idx, common->tkip_keymap);
+       clear_bit(key->hw_key_idx + 64, common->tkip_keymap);
+
        if (common->splitmic) {
                ath9k_hw_keyreset(ah, key->hw_key_idx + 32);
                clear_bit(key->hw_key_idx + 32, common->keymap);
                clear_bit(key->hw_key_idx + 64 + 32, common->keymap);
+
+               clear_bit(key->hw_key_idx + 32, common->tkip_keymap);
+               clear_bit(key->hw_key_idx + 64 + 32, common->tkip_keymap);
        }
 }
 EXPORT_SYMBOL(ath9k_cmn_key_delete);

diff --git a/drivers/net/wireless/ath/ath9k/mac.c b/drivers/net/wireless/ath/ath9k/mac.c
index e955bb9..0b7d125 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/mac.c
+++ b/drivers/net/wireless/ath/ath9k/mac.c
@@ -711,7 +711,8 @@ int ath9k_hw_rxprocdesc(struct ath_hw *ah, struct ath_desc *ds,
                        rs->rs_phyerr = phyerr;
                } else if (ads.ds_rxstatus8 & AR_DecryptCRCErr)
                        rs->rs_status |= ATH9K_RXERR_DECRYPT;
-               else if (ads.ds_rxstatus8 & AR_MichaelErr)
+               else if ((ads.ds_rxstatus8 & AR_MichaelErr) &&
+                        rs->rs_keyix != ATH9K_RXKEYIX_INVALID)
                        rs->rs_status |= ATH9K_RXERR_MIC;
        }
 

diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index a3fc987..534a91b 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -870,15 +870,18 @@ static bool ath9k_rx_accept(struct ath_common *common,
                if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
                        *decrypt_error = true;
                } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
-                       if (ieee80211_is_ctl(fc))
-                               /*
-                                * Sometimes, we get invalid
-                                * MIC failures on valid control frames.
-                                * Remove these mic errors.
-                                */
-                               rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
-                       else
+                       /*
+                        * The MIC error bit is only valid if the frame
+                        * is not a control frame or fragment, and it was
+                        * decrypted using a valid TKIP key.
+                        */
+                       if (!ieee80211_is_ctl(fc) &&
+                           !ieee80211_has_morefrags(fc) &&
+                           !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
+                           test_bit(rx_stats->rs_keyix, common->tkip_keymap))
                                rxs->flag |= RX_FLAG_MMIC_ERROR;
+                       else
+                               rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
                }
                /*
                 * Reject error frames with the exception of