Re: [mac80211] BUG_ON with current -git (4.8.0-11417-g24532f7)
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2016-10-12 14:22:28
Also in:
linux-next, linux-wireless, lkml
Subsystem:
mac80211, the rest · Maintainers:
Johannes Berg, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-10-14 · Re: [mac80211] BUG_ON with current -git (4.8.0-11417-g24532f7) · Ard Biesheuvel <hidden>
- 2016-10-14 · Re: [mac80211] BUG_ON with current -git (4.8.0-11417-g24532f7) · Johannes Berg <johannes@sipsolutions.net>
- 2016-10-14 · Re: [mac80211] BUG_ON with current -git (4.8.0-11417-g24532f7) · Ard Biesheuvel <hidden>
- 2016-10-14 · Re: [mac80211] BUG_ON with current -git (4.8.0-11417-g24532f7) · Johannes Berg <johannes@sipsolutions.net>
- 2016-10-14 · Re: [mac80211] BUG_ON with current -git (4.8.0-11417-g24532f7) · Ard Biesheuvel <hidden>
quoted
Can you elaborate on how exactly it kills your system?the last time I saw it it was a NULL deref at ieee80211_aes_ccm_decrypt.
Hm. I was expecting something within the crypto code would cause the crash, this seems strange. Anyway, I'm surely out of my depth wrt. the actual cause. Something like the patch below probably works around it, but it's horribly inefficient due to the locking and doesn't cover CMAC/GMAC either. johannes
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 103187ca9474..e820f437f02e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h@@ -27,6 +27,7 @@ #include <linux/leds.h> #include <linux/idr.h> #include <linux/rhashtable.h> +#include <crypto/aes.h> #include <net/ieee80211_radiotap.h> #include <net/cfg80211.h> #include <net/mac80211.h>
@@ -1224,6 +1225,10 @@ struct ieee80211_local { spinlock_t rx_path_lock; + /* temporary buffers for software crypto */ + u8 aad[2 * AES_BLOCK_SIZE]; + u8 b_0[AES_BLOCK_SIZE]; + /* Station data */ /* * The mutex only protects the list, hash table and
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index b48c1e13e281..a3f17a710b85 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c@@ -405,8 +405,8 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb, u8 *pos; u8 pn[6]; u64 pn64; - u8 aad[2 * AES_BLOCK_SIZE]; - u8 b_0[AES_BLOCK_SIZE]; + u8 *aad = tx->local->aad; + u8 *b_0 = tx->local->b_0; if (info->control.hw_key && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
@@ -460,9 +460,11 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb, return 0; pos += IEEE80211_CCMP_HDR_LEN; + spin_lock_bh(&tx->local->rx_path_lock); ccmp_special_blocks(skb, pn, b_0, aad); ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len, skb_put(skb, mic_len), mic_len); + spin_unlock_bh(&tx->local->rx_path_lock); return 0; }
@@ -534,8 +536,9 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx, } if (!(status->flag & RX_FLAG_DECRYPTED)) { - u8 aad[2 * AES_BLOCK_SIZE]; - u8 b_0[AES_BLOCK_SIZE]; + u8 *aad = rx->local->aad; + u8 *b_0 = rx->local->b_0; + /* hardware didn't decrypt/verify MIC */ ccmp_special_blocks(skb, pn, b_0, aad);
@@ -639,8 +642,8 @@ static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) u8 *pos; u8 pn[6]; u64 pn64; - u8 aad[2 * AES_BLOCK_SIZE]; - u8 j_0[AES_BLOCK_SIZE]; + u8 *aad = tx->local->aad; + u8 *j_0 = tx->local->b_0; if (info->control.hw_key && !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
@@ -695,9 +698,11 @@ static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) return 0; pos += IEEE80211_GCMP_HDR_LEN; + spin_lock_bh(&tx->local->rx_path_lock); gcmp_special_blocks(skb, pn, j_0, aad); ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len, skb_put(skb, IEEE80211_GCMP_MIC_LEN)); + spin_unlock_bh(&tx->local->rx_path_lock); return 0; }
@@ -764,8 +769,9 @@ ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx) } if (!(status->flag & RX_FLAG_DECRYPTED)) { - u8 aad[2 * AES_BLOCK_SIZE]; - u8 j_0[AES_BLOCK_SIZE]; + u8 *aad = rx->local->aad; + u8 *j_0 = rx->local->b_0; + /* hardware didn't decrypt/verify MIC */ gcmp_special_blocks(skb, pn, j_0, aad);