samba: fix CVE-2021-44758

Heimdal before 7.7.1 allows attackers to cause a NULL pointer
dereference in a SPNEGO acceptor via a preferred_mech_type of
GSS_C_NO_OID and a nonzero initial_response value to send_accept.

References:
https://nvd.nist.gov/vuln/detail/CVE-2021-44758

Upstream patches:
https://github.com/heimdal/heimdal/commit/f9ec7002cdd526ae84fbacbf153162e118f22580

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-networking/recipes-connectivity/samba/samba/CVE-2021-44758.patch

@@ -0,0 +1,72 @@
+From f9ec7002cdd526ae84fbacbf153162e118f22580 Mon Sep 17 00:00:00 2001
+From: Nicolas Williams <nico@twosigma.com>
+Date: Wed Mar 9 10:18:52 2022 -0600
+Subject: [PATCH] spnego: CVE-2021-44758 send_reject when no mech selected
+
+    This fixes a DoS where an initial SPNEGO token that has no acceptable
+    mechanisms causes a NULL dereference in acceptors.
+
+    send_accept() when called with a non-zero 'initial_response' did
+    not handle the case of gssspnego_ctx.preferred_mech_type equal
+    to GSS_C_NO_OID.
+
+    The failure to handle GSS_C_NO_OID has been present since the
+    initial revision of gssapi/spnego,
+    2baa7e7d613c26b2b037b368931519a84baec53d but might not have
+    been exercised until later revisions.
+
+    The introduction of opportunistic token handling in
+    gss_accept_sec_context(), 3c9d3266f47f594a29068c9d629908e7000ac663,
+    introduced two bugs:
+
+     1. The optional mechToken field is used unconditionally
+        possibly resulting in a segmentation fault.
+
+     2. If use of the opportunistic token is unsuccessful and the
+        mech type list length is one, send_accept() can be called
+        with 'initial_response' true and preferred mech set to
+        GSS_C_NO_OID.
+
+    b53c90da0890a9cce6f95c552f094ff6d69027bf ("Make error reporting
+    somewhat more correct for SPNEGO") attempted to fix the first
+    issue and increased the likelihood of the second.
+
+    This change alters the behavior of acceptor_start() so it calls
+    send_reject() when no mechanism was selected.
+
+Upstream-Status: Backport [https://github.com/heimdal/heimdal/commit/f9ec7002cdd526ae84fbacbf153162e118f22580]
+CVE: CVE-2021-44758
+
+Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
+---
+ .../heimdal/lib/gssapi/spnego/accept_sec_context.c | 14 ++++++++------
+ 1 file changed, 8 insertions(+), 6 deletions(-)
+
+diff --git a/lib/gssapi/spnego/accept_sec_context.c b/lib/gssapi/spnego/accept_sec_context.c
+index 3a51dd3..b60dc19 100644
+--- a/lib/gssapi/spnego/accept_sec_context.c
++++ b/lib/gssapi/spnego/accept_sec_context.c
+@@ -619,13 +619,15 @@ acceptor_start
+	    if (ret == 0)
+		break;
+	}
+-	if (preferred_mech_type == GSS_C_NO_OID) {
+-	    HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
+-	    free_NegotiationToken(&nt);
+-	    return ret;
+-	}
++    }
++
++    ctx->preferred_mech_type = preferred_mech_type;
+
+-	ctx->preferred_mech_type = preferred_mech_type;
++    if (preferred_mech_type == GSS_C_NO_OID) {
++        send_reject(minor_status, output_token);
++        HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
++        free_NegotiationToken(&nt);
++        return ret;
+     }
+
+     /*
+--
+2.40.0

meta-networking/recipes-connectivity/samba/samba_4.14.14.bb

@@ -32,6 +32,7 @@ SRC_URI = "${SAMBA_MIRROR}/stable/samba-${PV}.tar.gz \
            file://CVE-2022-3437-0008.patch;patchdir=source4/heimdal \
            file://CVE-2022-45142.patch;patchdir=source4/heimdal \
            file://CVE-2022-41916.patch;patchdir=source4/heimdal \
+           file://CVE-2021-44758.patch;patchdir=source4/heimdal \
            "
 
 SRC_URI:append:libc-musl = " \