hostapd: P2P: Fix a corner case in peer addition based on PD Request

[librecmc/librecmc.git] / package / network / services / hostapd / patches / 060-P2P-Fix-a-corner-case-in-peer-addition-based-on-PD-R.patch

diff --git a/package/network/services/hostapd/patches/060-P2P-Fix-a-corner-case-in-peer-addition-based-on-PD-R.patch b/package/network/services/hostapd/patches/060-P2P-Fix-a-corner-case-in-peer-addition-based-on-PD-R.patch
new file mode 100644 (file)
index 0000000..1202ff3
--- /dev/null
+++ b/package/network/services/hostapd/patches/060-P2P-Fix-a-corner-case-in-peer-addition-based-on-PD-R.patch
@@ -0,0 +1,45 @@
+From 8460e3230988ef2ec13ce6b69b687e941f6cdb32 Mon Sep 17 00:00:00 2001
+From: Jouni Malinen <jouni@codeaurora.org>
+Date: Tue, 8 Dec 2020 23:52:50 +0200
+Subject: [PATCH] P2P: Fix a corner case in peer addition based on PD Request
+
+p2p_add_device() may remove the oldest entry if there is no room in the
+peer table for a new peer. This would result in any pointer to that
+removed entry becoming stale. A corner case with an invalid PD Request
+frame could result in such a case ending up using (read+write) freed
+memory. This could only by triggered when the peer table has reached its
+maximum size and the PD Request frame is received from the P2P Device
+Address of the oldest remaining entry and the frame has incorrect P2P
+Device Address in the payload.
+
+Fix this by fetching the dev pointer again after having called
+p2p_add_device() so that the stale pointer cannot be used.
+
+Fixes: 17bef1e97a50 ("P2P: Add peer entry based on Provision Discovery Request")
+Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
+---
+ src/p2p/p2p_pd.c | 12 +++++-------
+ 1 file changed, 5 insertions(+), 7 deletions(-)
+
+--- a/src/p2p/p2p_pd.c
++++ b/src/p2p/p2p_pd.c
+@@ -595,14 +595,12 @@ void p2p_process_prov_disc_req(struct p2
+                       goto out;
+               }
+ 
++              dev = p2p_get_device(p2p, sa);
+               if (!dev) {
+-                      dev = p2p_get_device(p2p, sa);
+-                      if (!dev) {
+-                              p2p_dbg(p2p,
+-                                      "Provision Discovery device not found "
+-                                      MACSTR, MAC2STR(sa));
+-                              goto out;
+-                      }
++                      p2p_dbg(p2p,
++                              "Provision Discovery device not found "
++                              MACSTR, MAC2STR(sa));
++                      goto out;
+               }
+       } else if (msg.wfd_subelems) {
+               wpabuf_free(dev->info.wfd_subelems);