netdev - [PATCH] wireless: hostap: Fix a use after free in hostap_80211

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210329110021.7497-1-lyl2019@mail.ustc.edu.cn>
Date:   Mon, 29 Mar 2021 04:00:21 -0700
From:   Lv Yunlong <lyl2019@...l.ustc.edu.cn>
To:     j@...fi, kvalo@...eaurora.org, davem@...emloft.net, kuba@...nel.org
Cc:     linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, Lv Yunlong <lyl2019@...l.ustc.edu.cn>
Subject: [PATCH] wireless: hostap: Fix a use after free in hostap_80211_rx

Function hostap_80211_rx() calls prism2_rx_80211(..,skb,..). In
prism2_rx_80211, i found that the skb could be freed by dev_kfree_skb_any(skb)
and return 0. Also could be freed by netif_rx(skb) when netif_rx return
NET_RX_DROP.

But after called the prism2_rx_80211(..,skb,..), the skb is used by skb->len.

As the new skb->len is returned by prism2_rx_80211(), my patch uses a variable
len to repalce skb->len. According to another useage of prism2_rx_80211 in
monitor_rx().

Signed-off-by: Lv Yunlong <lyl2019@...l.ustc.edu.cn>
---
 drivers/net/wireless/intersil/hostap/hostap_80211_rx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intersil/hostap/hostap_80211_rx.c b/drivers/net/wireless/intersil/hostap/hostap_80211_rx.c
index 61be822f90b5..a45ee7b35533 100644
--- a/drivers/net/wireless/intersil/hostap/hostap_80211_rx.c
+++ b/drivers/net/wireless/intersil/hostap/hostap_80211_rx.c
@@ -1016,10 +1016,10 @@ void hostap_80211_rx(struct net_device *dev, struct sk_buff *skb,
 			if (local->hostapd && local->apdev) {
 				/* Send IEEE 802.1X frames to the user
 				 * space daemon for processing */
-				prism2_rx_80211(local->apdev, skb, rx_stats,
+				int len = prism2_rx_80211(local->apdev, skb, rx_stats,
 						PRISM2_RX_MGMT);
 				local->apdevstats.rx_packets++;
-				local->apdevstats.rx_bytes += skb->len;
+				local->apdevstats.rx_bytes += len;
 				goto rx_exit;
 			}
 		} else if (!frame_authorized) {
-- 
2.25.1