mac80211: ensure that mgmt tx skbs have tailroom for encryption (9d0f50b8) · Commits · 戴 / test

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 <nbd@nbd.name> Signed-off-by:

Johannes Berg <johannes.berg@intel.com>

net/mac80211/tx.c

+9 −3

Original line number	Diff line number	Diff line
		@@ -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);

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