[Midnightbsd-cvs] src [8267] trunk/sys/rpc/rpcsec_gss/svc_rpcsec_gss.c: add comment

[laffer1 at midnightbsd.org]

Revision: 8267
          http://svnweb.midnightbsd.org/src/?rev=8267
Author:   laffer1
Date:     2016-09-17 17:48:47 -0400 (Sat, 17 Sep 2016)
Log Message:
-----------
add comment

Modified Paths:
--------------
    trunk/sys/rpc/rpcsec_gss/svc_rpcsec_gss.c

Modified: trunk/sys/rpc/rpcsec_gss/svc_rpcsec_gss.c
===================================================================
--- trunk/sys/rpc/rpcsec_gss/svc_rpcsec_gss.c	2016-09-17 21:48:18 UTC (rev 8266)
+++ trunk/sys/rpc/rpcsec_gss/svc_rpcsec_gss.c	2016-09-17 21:48:47 UTC (rev 8267)
@@ -1024,6 +1024,17 @@
 	if (maj_stat != GSS_S_COMPLETE) {
 		rpc_gss_log_status("gss_verify_mic", client->cl_mech,
 		    maj_stat, min_stat);
+		/*
+		 * Attila Bogar and Herbert Poeckl reported similar problems
+		 * w.r.t. a Linux NFS client doing a krb5 NFS mount against the
+		 * FreeBSD server. We determined this was a Linux bug:
+		 * http://www.spinics.net/lists/linux-nfs/msg32466.html, where
+		 * the mount failed to work because a Destroy operation with a
+		 * bogus encrypted checksum destroyed the authenticator handle.
+		 * Since the checksum is bogus (gss_verify_mic() failed), it
+		 * doesn't make sense to destroy the handle and not doing so
+		 * fixes the Linux mount.
+		 */
 		if (gcproc != RPCSEC_GSS_DESTROY)
 			client->cl_state = CLIENT_STALE;
 		return (FALSE);