This is a note to let you know that I've just added the patch titled
wifi: cfg80211: Fix use after free for wext
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
wifi-cfg80211-fix-use-after-free-for-wext.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 015b8cc5e7c4d7bb671f1984d7b7338c310b185b Mon Sep 17 00:00:00 2001
From: Alexander Wetzel <alexander@xxxxxxxxxxxxxx>
Date: Tue, 24 Jan 2023 15:18:56 +0100
Subject: wifi: cfg80211: Fix use after free for wext
From: Alexander Wetzel <alexander@xxxxxxxxxxxxxx>
commit 015b8cc5e7c4d7bb671f1984d7b7338c310b185b upstream.
Key information in wext.connect is not reset on (re)connect and can hold
data from a previous connection.
Reset key data to avoid that drivers or mac80211 incorrectly detect a
WEP connection request and access the freed or already reused memory.
Additionally optimize cfg80211_sme_connect() and avoid an useless
schedule of conn_work.
Fixes: fffd0934b939 ("cfg80211: rework key operation")
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20230124141856.356646-1-alexander@xxxxxxxxxxxxxx
Signed-off-by: Alexander Wetzel <alexander@xxxxxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/wireless/sme.c | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -269,6 +269,15 @@ void cfg80211_conn_work(struct work_stru
rtnl_unlock();
}
+static void cfg80211_step_auth_next(struct cfg80211_conn *conn,
+ struct cfg80211_bss *bss)
+{
+ memcpy(conn->bssid, bss->bssid, ETH_ALEN);
+ conn->params.bssid = conn->bssid;
+ conn->params.channel = bss->channel;
+ conn->state = CFG80211_CONN_AUTHENTICATE_NEXT;
+}
+
/* Returned bss is reference counted and must be cleaned up appropriately. */
static struct cfg80211_bss *cfg80211_get_conn_bss(struct wireless_dev *wdev)
{
@@ -286,10 +295,7 @@ static struct cfg80211_bss *cfg80211_get
if (!bss)
return NULL;
- memcpy(wdev->conn->bssid, bss->bssid, ETH_ALEN);
- wdev->conn->params.bssid = wdev->conn->bssid;
- wdev->conn->params.channel = bss->channel;
- wdev->conn->state = CFG80211_CONN_AUTHENTICATE_NEXT;
+ cfg80211_step_auth_next(wdev->conn, bss);
schedule_work(&rdev->conn_work);
return bss;
@@ -568,7 +574,12 @@ static int cfg80211_sme_connect(struct w
wdev->conn->params.ssid_len = wdev->ssid_len;
/* see if we have the bss already */
- bss = cfg80211_get_conn_bss(wdev);
+ bss = cfg80211_get_bss(wdev->wiphy, wdev->conn->params.channel,
+ wdev->conn->params.bssid,
+ wdev->conn->params.ssid,
+ wdev->conn->params.ssid_len,
+ wdev->conn_bss_type,
+ IEEE80211_PRIVACY(wdev->conn->params.privacy));
if (prev_bssid) {
memcpy(wdev->conn->prev_bssid, prev_bssid, ETH_ALEN);
@@ -579,6 +590,7 @@ static int cfg80211_sme_connect(struct w
if (bss) {
enum nl80211_timeout_reason treason;
+ cfg80211_step_auth_next(wdev->conn, bss);
err = cfg80211_conn_do_work(wdev, &treason);
cfg80211_put_bss(wdev->wiphy, bss);
} else {
@@ -1207,6 +1219,15 @@ int cfg80211_connect(struct cfg80211_reg
} else {
if (WARN_ON(connkeys))
return -EINVAL;
+
+ /* connect can point to wdev->wext.connect which
+ * can hold key data from a previous connection
+ */
+ connect->key = NULL;
+ connect->key_len = 0;
+ connect->key_idx = 0;
+ connect->crypto.cipher_group = 0;
+ connect->crypto.n_ciphers_pairwise = 0;
}
wdev->connect_keys = connkeys;
Patches currently in stable-queue which might be from alexander@xxxxxxxxxxxxxx are
queue-4.19/wifi-cfg80211-fix-use-after-free-for-wext.patch
