From: Johannes Berg <johannes.berg@xxxxxxxxx>
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 <johannes.berg@xxxxxxxxx>
---
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 b4e29f9c73c8..2ca132146a79 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;
--
2.1.4
--
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