The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 65c415a144ad8132b6a6d97d4a1919ffc728e2d1 Mon Sep 17 00:00:00 2001

From: Wen Gong wgong@codeaurora.org Date: Tue, 11 May 2021 20:02:53 +0200 Subject: [PATCH] ath10k: drop fragments with multicast DA for PCIe

Fragmentation is not used with multicast frames. Discard unexpected fragments with multicast DA. This fixes CVE-2020-26145.

Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00110-QCARMSWP-1

Cc: stable@vger.kernel.org Signed-off-by: Wen Gong wgong@codeaurora.org Signed-off-by: Jouni Malinen jouni@codeaurora.org Link: https://lore.kernel.org/r/20210511200110.5a0bd289bda8.Idd6ebea20038fb1cfee6d... Signed-off-by: Johannes Berg johannes.berg@intel.com

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c index f1e5bce8b14f..cb04848ed5cb 100644 --- a/drivers/net/wireless/ath/ath10k/htt_rx.c +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c @@ -1768,6 +1768,16 @@ static u64 ath10k_htt_rx_h_get_pn(struct ath10k *ar, struct sk_buff *skb, return pn; }

+static bool ath10k_htt_rx_h_frag_multicast_check(struct ath10k *ar, + struct sk_buff *skb, + u16 offset) +{ + struct ieee80211_hdr *hdr; + + hdr = (struct ieee80211_hdr *)(skb->data + offset); + return !is_multicast_ether_addr(hdr->addr1); +} + static bool ath10k_htt_rx_h_frag_pn_check(struct ath10k *ar, struct sk_buff *skb, u16 peer_id, @@ -1839,7 +1849,7 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar, bool is_decrypted; bool is_mgmt; u32 attention; - bool frag_pn_check = true; + bool frag_pn_check = true, multicast_check = true;

if (skb_queue_empty(amsdu)) return; @@ -1946,13 +1956,20 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar, 0, enctype);

- if (!frag_pn_check) { - /* Discard the fragment with invalid PN */ + if (frag) + multicast_check = ath10k_htt_rx_h_frag_multicast_check(ar, + msdu, + 0); + + if (!frag_pn_check || !multicast_check) { + /* Discard the fragment with invalid PN or multicast DA + */ temp = msdu->prev; __skb_unlink(msdu, amsdu); dev_kfree_skb_any(msdu); msdu = temp; frag_pn_check = true; + multicast_check = true; continue; }