[PATCH] hostapd: Fix crash setting global configurator params on chirp rx

Andrew Beltrano anbeltra at microsoft.com
Wed Sep 16 17:51:40 EDT 2020

When a presence announcement frame is received, a check is done to
ensure an ongoing auth is not in progress (!hapd->dpp_auth). A new dpp
auth is then initialized, however, when setting global configurator
params for it, the hapd->dpp_auth pointer is used which was earlier
confirmed as NULL, causing a crash in dpp_set_configurator params when
the pointer is dereferenced.

This only occurs when there are global DPP configurator params to be set
and the peer has no overriding configurator params. If no global dpp
configurator params exist, the call to dpp_set_configurator exits early
and the problem is not observed.

Fix by using the newly init'ed dpp auth structure for setting global
dpp configurator params.

Signed-off-by: Andrew Beltrano <anbeltra at microsoft.com>
This problem does not exist in the presence announcement rx handler in
wpa_supplicant as it correctly uses the newly init'ed dpp auth to set
the global dpp configurator params.
 src/ap/dpp_hostapd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/ap/dpp_hostapd.c b/src/ap/dpp_hostapd.c
index 15aa82b85..2a28239e1 100644
--- a/src/ap/dpp_hostapd.c
+++ b/src/ap/dpp_hostapd.c
@@ -1249,8 +1249,8 @@ hostapd_dpp_rx_presence_announcement(struct hostapd_data *hapd, const u8 *src,
 	if (!auth)
-	hostapd_dpp_set_testing_options(hapd, hapd->dpp_auth);
-	if (dpp_set_configurator(hapd->dpp_auth,
+	hostapd_dpp_set_testing_options(hapd, auth);
+	if (dpp_set_configurator(auth,
 				 hapd->dpp_configurator_params) < 0) {

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