From: Vladimir Kondratiev Date: Tue, 1 Mar 2016 17:18:07 +0000 (+0200) Subject: wil6210: replay attack detection X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=58527421489dcc1110f6bcfd3b50d479199af4e0;p=linux-beck.git wil6210: replay attack detection Check PN for encrypted frames. Maintain PN data for Rx keys, pairwise per TID and group. Print PN's in the debugfs "stations" entry, like: [0] 04:ce:14:0a:3c:3d connected [ 0] ([32] 0 TU) 0x0fe [____________________________|___] total 252 drop 0 (dup 0 + old 0) last 0x000 [ 0] PN [0+]000000000000 [1-]000000000000 [2-]000000000000 [3-]000000000000 [GR] PN [0-]000000000000 [1+]000000000000 [2+]000000000000 [3-]000000000000 Rx invalid frame: non-data 0, short 0, large 0, replay 0 Rx/MCS: 0 110 65 65 65 0 12 0 0 0 0 0 0 [1] 00:00:00:00:00:00 unused [2] 00:00:00:00:00:00 unused [3] 00:00:00:00:00:00 unused [4] 00:00:00:00:00:00 unused [5] 00:00:00:00:00:00 unused [6] 00:00:00:00:00:00 unused [7] 00:00:00:00:00:00 unused Signed-off-by: Vladimir Kondratiev Signed-off-by: Hamad Kadmany Signed-off-by: Maya Erez Signed-off-by: Kalle Valo --- diff --git a/drivers/net/wireless/ath/wil6210/cfg80211.c b/drivers/net/wireless/ath/wil6210/cfg80211.c index 11f1bb8dfebe..ddadda90cfa0 100644 --- a/drivers/net/wireless/ath/wil6210/cfg80211.c +++ b/drivers/net/wireless/ath/wil6210/cfg80211.c @@ -82,6 +82,12 @@ static const u32 wil_cipher_suites[] = { WLAN_CIPHER_SUITE_GCMP, }; +static const char * const key_usage_str[] = { + [WMI_KEY_USE_PAIRWISE] = "PTK", + [WMI_KEY_USE_RX_GROUP] = "RX_GTK", + [WMI_KEY_USE_TX_GROUP] = "TX_GTK", +}; + int wil_iftype_nl2wmi(enum nl80211_iftype type) { static const struct { @@ -610,11 +616,6 @@ static enum wmi_key_usage wil_detect_key_usage(struct wil6210_priv *wil, { struct wireless_dev *wdev = wil->wdev; enum wmi_key_usage rc; - static const char * const key_usage_str[] = { - [WMI_KEY_USE_PAIRWISE] = "WMI_KEY_USE_PAIRWISE", - [WMI_KEY_USE_RX_GROUP] = "WMI_KEY_USE_RX_GROUP", - [WMI_KEY_USE_TX_GROUP] = "WMI_KEY_USE_TX_GROUP", - }; if (pairwise) { rc = WMI_KEY_USE_PAIRWISE; @@ -638,20 +639,86 @@ static enum wmi_key_usage wil_detect_key_usage(struct wil6210_priv *wil, return rc; } +static struct wil_tid_crypto_rx_single * +wil_find_crypto_ctx(struct wil6210_priv *wil, u8 key_index, + enum wmi_key_usage key_usage, const u8 *mac_addr) +{ + int cid = -EINVAL; + int tid = 0; + struct wil_sta_info *s; + struct wil_tid_crypto_rx *c; + + if (key_usage == WMI_KEY_USE_TX_GROUP) + return NULL; /* not needed */ + + /* supplicant provides Rx group key in STA mode with NULL MAC address */ + if (mac_addr) + cid = wil_find_cid(wil, mac_addr); + else if (key_usage == WMI_KEY_USE_RX_GROUP) + cid = wil_find_cid_by_idx(wil, 0); + if (cid < 0) { + wil_err(wil, "No CID for %pM %s[%d]\n", mac_addr, + key_usage_str[key_usage], key_index); + return ERR_PTR(cid); + } + + s = &wil->sta[cid]; + if (key_usage == WMI_KEY_USE_PAIRWISE) + c = &s->tid_crypto_rx[tid]; + else + c = &s->group_crypto_rx; + + return &c->key_id[key_index]; +} + static int wil_cfg80211_add_key(struct wiphy *wiphy, struct net_device *ndev, u8 key_index, bool pairwise, const u8 *mac_addr, struct key_params *params) { + int rc; struct wil6210_priv *wil = wiphy_to_wil(wiphy); enum wmi_key_usage key_usage = wil_detect_key_usage(wil, pairwise); + struct wil_tid_crypto_rx_single *cc = wil_find_crypto_ctx(wil, + key_index, + key_usage, + mac_addr); + + wil_dbg_misc(wil, "%s(%pM %s[%d] PN %*phN)\n", __func__, + mac_addr, key_usage_str[key_usage], key_index, + params->seq_len, params->seq); + + if (IS_ERR(cc)) { + wil_err(wil, "Not connected, %s(%pM %s[%d] PN %*phN)\n", + __func__, mac_addr, key_usage_str[key_usage], key_index, + params->seq_len, params->seq); + return -EINVAL; + } + + if (cc) + cc->key_set = false; - wil_dbg_misc(wil, "%s(%pM[%d] %s)\n", __func__, mac_addr, key_index, - pairwise ? "PTK" : "GTK"); + if (params->seq && params->seq_len != IEEE80211_GCMP_PN_LEN) { + wil_err(wil, + "Wrong PN len %d, %s(%pM %s[%d] PN %*phN)\n", + params->seq_len, __func__, mac_addr, + key_usage_str[key_usage], key_index, + params->seq_len, params->seq); + return -EINVAL; + } - return wmi_add_cipher_key(wil, key_index, mac_addr, params->key_len, - params->key, key_usage); + rc = wmi_add_cipher_key(wil, key_index, mac_addr, params->key_len, + params->key, key_usage); + if ((rc == 0) && cc) { + if (params->seq) + memcpy(cc->pn, params->seq, IEEE80211_GCMP_PN_LEN); + else + memset(cc->pn, 0, IEEE80211_GCMP_PN_LEN); + cc->key_set = true; + } + + return rc; } static int wil_cfg80211_del_key(struct wiphy *wiphy, @@ -661,9 +728,20 @@ static int wil_cfg80211_del_key(struct wiphy *wiphy, { struct wil6210_priv *wil = wiphy_to_wil(wiphy); enum wmi_key_usage key_usage = wil_detect_key_usage(wil, pairwise); + struct wil_tid_crypto_rx_single *cc = wil_find_crypto_ctx(wil, + key_index, + key_usage, + mac_addr); + + wil_dbg_misc(wil, "%s(%pM %s[%d])\n", __func__, mac_addr, + key_usage_str[key_usage], key_index); + + if (IS_ERR(cc)) + wil_info(wil, "Not connected, %s(%pM %s[%d])\n", __func__, + mac_addr, key_usage_str[key_usage], key_index); - wil_dbg_misc(wil, "%s(%pM[%d] %s)\n", __func__, mac_addr, key_index, - pairwise ? "PTK" : "GTK"); + if (!IS_ERR_OR_NULL(cc)) + cc->key_set = false; return wmi_del_cipher_key(wil, key_index, mac_addr, key_usage); } diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c index 3bbe73b6d05a..d80bb75c6576 100644 --- a/drivers/net/wireless/ath/wil6210/debugfs.c +++ b/drivers/net/wireless/ath/wil6210/debugfs.c @@ -1333,6 +1333,34 @@ static void wil_print_rxtid(struct seq_file *s, struct wil_tid_ampdu_rx *r) r->ssn_last_drop); } +static void wil_print_rxtid_crypto(struct seq_file *s, int tid, + struct wil_tid_crypto_rx *c) +{ + int i; + + for (i = 0; i < 4; i++) { + struct wil_tid_crypto_rx_single *cc = &c->key_id[i]; + + if (cc->key_set) + goto has_keys; + } + return; + +has_keys: + if (tid < WIL_STA_TID_NUM) + seq_printf(s, " [%2d] PN", tid); + else + seq_puts(s, " [GR] PN"); + + for (i = 0; i < 4; i++) { + struct wil_tid_crypto_rx_single *cc = &c->key_id[i]; + + seq_printf(s, " [%i%s]%6phN", i, cc->key_set ? "+" : "-", + cc->pn); + } + seq_puts(s, "\n"); +} + static int wil_sta_debugfs_show(struct seq_file *s, void *data) __acquires(&p->tid_rx_lock) __releases(&p->tid_rx_lock) { @@ -1360,18 +1388,25 @@ __acquires(&p->tid_rx_lock) __releases(&p->tid_rx_lock) spin_lock_bh(&p->tid_rx_lock); for (tid = 0; tid < WIL_STA_TID_NUM; tid++) { struct wil_tid_ampdu_rx *r = p->tid_rx[tid]; + struct wil_tid_crypto_rx *c = + &p->tid_crypto_rx[tid]; if (r) { - seq_printf(s, "[%2d] ", tid); + seq_printf(s, " [%2d] ", tid); wil_print_rxtid(s, r); } + + wil_print_rxtid_crypto(s, tid, c); } + wil_print_rxtid_crypto(s, WIL_STA_TID_NUM, + &p->group_crypto_rx); spin_unlock_bh(&p->tid_rx_lock); seq_printf(s, - "Rx invalid frame: non-data %lu, short %lu, large %lu\n", + "Rx invalid frame: non-data %lu, short %lu, large %lu, replay %lu\n", p->stats.rx_non_data_frame, p->stats.rx_short_frame, - p->stats.rx_large_frame); + p->stats.rx_large_frame, + p->stats.rx_replay); seq_puts(s, "Rx/MCS:"); for (mcs = 0; mcs < ARRAY_SIZE(p->stats.rx_per_mcs); diff --git a/drivers/net/wireless/ath/wil6210/main.c b/drivers/net/wireless/ath/wil6210/main.c index 997a740e0a4b..1fa215d0eeed 100644 --- a/drivers/net/wireless/ath/wil6210/main.c +++ b/drivers/net/wireless/ath/wil6210/main.c @@ -149,7 +149,7 @@ __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock) might_sleep(); wil_dbg_misc(wil, "%s(CID %d, status %d)\n", __func__, cid, sta->status); - + /* inform upper/lower layers */ if (sta->status != wil_sta_unused) { if (!from_event) wmi_disconnect_sta(wil, sta->addr, reason_code, true); @@ -165,7 +165,7 @@ __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock) } sta->status = wil_sta_unused; } - + /* reorder buffers */ for (i = 0; i < WIL_STA_TID_NUM; i++) { struct wil_tid_ampdu_rx *r; @@ -177,10 +177,15 @@ __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock) spin_unlock_bh(&sta->tid_rx_lock); } + /* crypto context */ + memset(sta->tid_crypto_rx, 0, sizeof(sta->tid_crypto_rx)); + memset(&sta->group_crypto_rx, 0, sizeof(sta->group_crypto_rx)); + /* release vrings */ for (i = 0; i < ARRAY_SIZE(wil->vring_tx); i++) { if (wil->vring2cid_tid[i][0] == cid) wil_vring_fini_tx(wil, i); } + /* statistics */ memset(&sta->stats, 0, sizeof(sta->stats)); } diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c index 6af20903cf89..f383001b86aa 100644 --- a/drivers/net/wireless/ath/wil6210/txrx.c +++ b/drivers/net/wireless/ath/wil6210/txrx.c @@ -549,6 +549,60 @@ static int wil_rx_refill(struct wil6210_priv *wil, int count) return rc; } +/** + * reverse_memcmp - Compare two areas of memory, in reverse order + * @cs: One area of memory + * @ct: Another area of memory + * @count: The size of the area. + * + * Cut'n'paste from original memcmp (see lib/string.c) + * with minimal modifications + */ +static int reverse_memcmp(const void *cs, const void *ct, size_t count) +{ + const unsigned char *su1, *su2; + int res = 0; + + for (su1 = cs + count - 1, su2 = ct + count - 1; count > 0; + --su1, --su2, count--) { + res = *su1 - *su2; + if (res) + break; + } + return res; +} + +static int wil_rx_crypto_check(struct wil6210_priv *wil, struct sk_buff *skb) +{ + struct vring_rx_desc *d = wil_skb_rxdesc(skb); + int cid = wil_rxdesc_cid(d); + int tid = wil_rxdesc_tid(d); + int key_id = wil_rxdesc_key_id(d); + int mc = wil_rxdesc_mcast(d); + struct wil_sta_info *s = &wil->sta[cid]; + struct wil_tid_crypto_rx *c = mc ? &s->group_crypto_rx : + &s->tid_crypto_rx[tid]; + struct wil_tid_crypto_rx_single *cc = &c->key_id[key_id]; + const u8 *pn = (u8 *)&d->mac.pn_15_0; + + if (!cc->key_set) { + wil_err_ratelimited(wil, + "Key missing. CID %d TID %d MCast %d KEY_ID %d\n", + cid, tid, mc, key_id); + return -EINVAL; + } + + if (reverse_memcmp(pn, cc->pn, IEEE80211_GCMP_PN_LEN) <= 0) { + wil_err_ratelimited(wil, + "Replay attack. CID %d TID %d MCast %d KEY_ID %d PN %6phN last %6phN\n", + cid, tid, mc, key_id, pn, cc->pn); + return -EINVAL; + } + memcpy(cc->pn, pn, IEEE80211_GCMP_PN_LEN); + + return 0; +} + /* * Pass Rx packet to the netif. Update statistics. * Called in softirq context (NAPI poll). @@ -561,6 +615,7 @@ void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev) unsigned int len = skb->len; struct vring_rx_desc *d = wil_skb_rxdesc(skb); int cid = wil_rxdesc_cid(d); /* always 0..7, no need to check */ + int security = wil_rxdesc_security(d); struct ethhdr *eth = (void *)skb->data; /* here looking for DA, not A1, thus Rxdesc's 'mcast' indication * is not suitable, need to look at data @@ -586,6 +641,13 @@ void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev) skb_orphan(skb); + if (security && (wil_rx_crypto_check(wil, skb) != 0)) { + rc = GRO_DROP; + dev_kfree_skb(skb); + stats->rx_replay++; + goto stats; + } + if (wdev->iftype == NL80211_IFTYPE_AP && !wil->ap_isolate) { if (mcast) { /* send multicast frames both to higher layers in @@ -627,6 +689,7 @@ void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev) wil_dbg_txrx(wil, "Rx complete %d bytes => %s\n", len, gro_res_str[rc]); } +stats: /* statistics. rc set to GRO_NORMAL for AP bridging */ if (unlikely(rc == GRO_DROP)) { ndev->stats.rx_dropped++; diff --git a/drivers/net/wireless/ath/wil6210/txrx.h b/drivers/net/wireless/ath/wil6210/txrx.h index ee7c7b4b9a17..fcdffaa8251b 100644 --- a/drivers/net/wireless/ath/wil6210/txrx.h +++ b/drivers/net/wireless/ath/wil6210/txrx.h @@ -1,5 +1,5 @@ /* - * Copyright (c) 2012-2014 Qualcomm Atheros, Inc. + * Copyright (c) 2012-2016 Qualcomm Atheros, Inc. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above @@ -480,6 +480,16 @@ static inline int wil_rxdesc_ext_subtype(struct vring_rx_desc *d) return WIL_GET_BITS(d->mac.d0, 28, 31); } +static inline int wil_rxdesc_key_id(struct vring_rx_desc *d) +{ + return WIL_GET_BITS(d->mac.d1, 4, 5); +} + +static inline int wil_rxdesc_security(struct vring_rx_desc *d) +{ + return WIL_GET_BITS(d->mac.d1, 7, 7); +} + static inline int wil_rxdesc_ds_bits(struct vring_rx_desc *d) { return WIL_GET_BITS(d->mac.d1, 8, 9); diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h index d59c3f29941e..44ff040e2fea 100644 --- a/drivers/net/wireless/ath/wil6210/wil6210.h +++ b/drivers/net/wireless/ath/wil6210/wil6210.h @@ -455,6 +455,21 @@ struct wil_tid_ampdu_rx { bool first_time; /* is it 1-st time this buffer used? */ }; +/** + * struct wil_tid_crypto_rx_single - TID crypto information (Rx). + * + * @pn: GCMP PN for the session + * @key_set: valid key present + */ +struct wil_tid_crypto_rx_single { + u8 pn[IEEE80211_GCMP_PN_LEN]; + bool key_set; +}; + +struct wil_tid_crypto_rx { + struct wil_tid_crypto_rx_single key_id[4]; +}; + enum wil_sta_status { wil_sta_unused = 0, wil_sta_conn_pending = 1, @@ -474,6 +489,7 @@ struct wil_net_stats { unsigned long rx_non_data_frame; unsigned long rx_short_frame; unsigned long rx_large_frame; + unsigned long rx_replay; u16 last_mcs_rx; u64 rx_per_mcs[WIL_MCS_MAX + 1]; }; @@ -495,6 +511,8 @@ struct wil_sta_info { spinlock_t tid_rx_lock; /* guarding tid_rx array */ unsigned long tid_rx_timer_expired[BITS_TO_LONGS(WIL_STA_TID_NUM)]; unsigned long tid_rx_stop_requested[BITS_TO_LONGS(WIL_STA_TID_NUM)]; + struct wil_tid_crypto_rx tid_crypto_rx[WIL_STA_TID_NUM]; + struct wil_tid_crypto_rx group_crypto_rx; }; enum {