From 30679ec409189de89f55552a623c264091d72b66 Mon Sep 17 00:00:00 2001 From: Karthikeyan Periyasamy Date: Wed, 27 Nov 2019 14:08:53 +0000 Subject: [PATCH] ath11k: avoid use_after_free in ath11k_dp_rx_msdu_coalesce API Accessing already stored first msdu data after the skb expand trigger use_after_free, since first msdu got deleted. so do the descriptor copy operation before the skb expand operation. Signed-off-by: Karthikeyan Periyasamy Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath11k/dp_rx.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c index 67efa24..f87bd32 100644 --- a/drivers/net/wireless/ath/ath11k/dp_rx.c +++ b/drivers/net/wireless/ath/ath11k/dp_rx.c @@ -1376,6 +1376,11 @@ static int ath11k_dp_rx_msdu_coalesce(struct ath11k *ar, skb_put(first, DP_RX_BUFFER_SIZE); skb_pull(first, buf_first_hdr_len); + /* When an MSDU spread over multiple buffers attention, MSDU_END and + * MPDU_END tlvs are valid only in the last buffer. Copy those tlvs. + */ + ath11k_dp_rx_desc_end_tlv_copy(rxcb->rx_desc, ldesc); + space_extra = msdu_len - (buf_first_len + skb_tailroom(first)); if (space_extra > 0 && (pskb_expand_head(first, 0, space_extra, GFP_ATOMIC) < 0)) { @@ -1391,11 +1396,6 @@ static int ath11k_dp_rx_msdu_coalesce(struct ath11k *ar, return -ENOMEM; } - /* When an MSDU spread over multiple buffers attention, MSDU_END and - * MPDU_END tlvs are valid only in the last buffer. Copy those tlvs. - */ - ath11k_dp_rx_desc_end_tlv_copy(rxcb->rx_desc, ldesc); - rem_len = msdu_len - buf_first_len; while ((skb = __skb_dequeue(msdu_list)) != NULL && rem_len > 0) { rxcb = ATH11K_SKB_RXCB(skb); -- 2.7.4