From 9d0f50b80222dc273e67e4e14410fcfa4130a90c Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Tue, 29 Jan 2019 11:10:57 +0100 Subject: [PATCH] mac80211: ensure that mgmt tx skbs have tailroom for encryption Some drivers use IEEE80211_KEY_FLAG_SW_MGMT_TX to indicate that management frames need to be software encrypted. Since normal data packets are still encrypted by the hardware, crypto_tx_tailroom_needed_cnt gets decremented after key upload to hw. This can lead to passing skbs to ccmp_encrypt_skb, which don't have the necessary tailroom for software encryption. Change the code to add tailroom for encrypted management packets, even if crypto_tx_tailroom_needed_cnt is 0. Cc: stable@vger.kernel.org Signed-off-by: Felix Fietkau Signed-off-by: Johannes Berg --- net/mac80211/tx.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index f170d6c6629a..928f13a208b0 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -1938,9 +1938,16 @@ static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata, int head_need, bool may_encrypt) { struct ieee80211_local *local = sdata->local; + struct ieee80211_hdr *hdr; + bool enc_tailroom; int tail_need = 0; - if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) { + hdr = (struct ieee80211_hdr *) skb->data; + enc_tailroom = may_encrypt && + (sdata->crypto_tx_tailroom_needed_cnt || + ieee80211_is_mgmt(hdr->frame_control)); + + if (enc_tailroom) { tail_need = IEEE80211_ENCRYPT_TAILROOM; tail_need -= skb_tailroom(skb); tail_need = max_t(int, tail_need, 0); @@ -1948,8 +1955,7 @@ static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata, if (skb_cloned(skb) && (!ieee80211_hw_check(&local->hw, SUPPORTS_CLONED_SKBS) || - !skb_clone_writable(skb, ETH_HLEN) || - (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt))) + !skb_clone_writable(skb, ETH_HLEN) || enc_tailroom)) I802_DEBUG_INC(local->tx_expand_skb_head_cloned); else if (head_need || tail_need) I802_DEBUG_INC(local->tx_expand_skb_head);