wpa-supplicant: fix CVE-2021-27803

A vulnerability was discovered in how p2p/p2p_pd.c in wpa_supplicant
before 2.10 processes P2P (Wi-Fi Direct) provision discovery requests.
It could result in denial of service or other impact (potentially
execution of arbitrary code), for an attacker within radio range.

References:
https://nvd.nist.gov/vuln/detail/CVE-2021-27803

Upstream patches:
https://w1.fi/cgit/hostap/commit/?id=8460e3230988ef2ec13ce6b69b687e941f6cdb32

(From OE-Core rev: 81e4260b83c52558c320fd7d1c1eafcb312ad6be)

Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 59 insertions, 0 deletions

diff --git a/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/CVE-2021-27803.patch b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/CVE-2021-27803.patch
new file mode 100644
index 0000000000..004b1dbd19
--- /dev/null
+++ b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/CVE-2021-27803.patch
@@ -0,0 +1,58 @@
+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>
+
+Upstream-Status: Backport
+CVE: CVE-2021-27803
+
+Reference to upstream patch:
+[https://w1.fi/cgit/hostap/commit/?id=8460e3230988ef2ec13ce6b69b687e941f6cdb32]
+
+Signed-off-by: Stefan Ghinea <stefan.ghinea@windriver.com>
+---
+ src/p2p/p2p_pd.c | 12 +++++-------
+ 1 file changed, 5 insertions(+), 7 deletions(-)
+
+diff --git a/src/p2p/p2p_pd.c b/src/p2p/p2p_pd.c
+index 3994ec0..05fd593 100644
+--- a/src/p2p/p2p_pd.c
++++ b/src/p2p/p2p_pd.c
+@@ -595,14 +595,12 @@ void p2p_process_prov_disc_req(struct p2p_data *p2p, const u8 *sa,
+                        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);
+-- 
+2.17.1
+
diff --git a/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant_2.9.bb b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant_2.9.bb
index caa6018ce8..357c28634a 100644
--- a/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant_2.9.bb
+++ b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant_2.9.bb
@@ -31,6 +31,7 @@ SRC_URI = "http://w1.fi/releases/wpa_supplicant-${PV}.tar.gz  \
            file://0002-WPS-UPnP-Fix-event-message-generation-using-a-long-U.patch \
            file://0003-WPS-UPnP-Handle-HTTP-initiation-failures-for-events-.patch \
            file://CVE-2021-0326.patch \
+           file://CVE-2021-27803.patch \
           "
 SRC_URI[md5sum] = "2d2958c782576dc9901092fbfecb4190"
 SRC_URI[sha256sum] = "fcbdee7b4a64bea8177973299c8c824419c413ec2e3a95db63dd6a5dc3541f17"