From e3a55b5399d55200c024fe0c2984dc7ad049da44 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 5 May 2015 16:32:29 +0200 Subject: [PATCH] mac80211: validate cipher scheme PN length better Currently, a cipher scheme can advertise an arbitrarily long sequence counter, but mac80211 only supports up to 16 bytes and the initial value from userspace will be truncated. Fix two things: * don't allow the driver to register anything longer than the 16 bytes that mac80211 reserves space for * require userspace to specify a starting value with the correct length (or none at all) Signed-off-by: Johannes Berg --- net/mac80211/key.c | 10 ++++++---- net/mac80211/main.c | 5 ++++- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/net/mac80211/key.c b/net/mac80211/key.c index 0a5d5c5ad30f..2e677376c958 100644 --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -485,15 +485,17 @@ ieee80211_key_alloc(u32 cipher, int idx, size_t key_len, break; default: if (cs) { - size_t len = (seq_len > IEEE80211_MAX_PN_LEN) ? - IEEE80211_MAX_PN_LEN : seq_len; + if (seq_len && seq_len != cs->pn_len) { + kfree(key); + return ERR_PTR(-EINVAL); + } key->conf.iv_len = cs->hdr_len; key->conf.icv_len = cs->mic_len; for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++) - for (j = 0; j < len; j++) + for (j = 0; j < seq_len; j++) key->u.gen.rx_pn[i][j] = - seq[len - j - 1]; + seq[seq_len - j - 1]; key->flags |= KEY_FLAG_CIPHER_SCHEME; } } diff --git a/net/mac80211/main.c b/net/mac80211/main.c index effe9d39cd7e..3c956c5f99b2 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -768,8 +768,11 @@ static int ieee80211_init_cipher_suites(struct ieee80211_local *local) suites[w++] = WLAN_CIPHER_SUITE_BIP_GMAC_256; } - for (r = 0; r < local->hw.n_cipher_schemes; r++) + for (r = 0; r < local->hw.n_cipher_schemes; r++) { suites[w++] = cs[r].cipher; + if (WARN_ON(cs[r].pn_len > IEEE80211_MAX_PN_LEN)) + return -EINVAL; + } } local->hw.wiphy->cipher_suites = suites; -- 2.20.1