[ovs-dev] [PATCH] ofp-group: Don't assert-fail decoding bad OF1.5 group mod type or command.

[Ben Pfaff]

When decoding a group mod, the current code validates the group type and
command after the whole group mod has been decoded.  The OF1.5 decoder,
however, tries to use the type and command earlier, when it might still be
invalid.  This caused an assertion failure (via OVS_NOT_REACHED).  This
commit fixes the problem.

ovs-vswitchd does not enable support for OpenFlow 1.5 by default.

Reported-at: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=9249
Signed-off-by: Ben Pfaff <blp at ovn.org>
---
 lib/ofp-group.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/ofp-group.c b/lib/ofp-group.c
index 697208f0e9f6..f6e5242f5244 100644
--- a/lib/ofp-group.c
+++ b/lib/ofp-group.c
@@ -1547,7 +1547,7 @@ parse_group_prop_ntr_selection_method(struct ofpbuf *payload,
                     "only allowed for select groups");
         return OFPERR_OFPBPC_BAD_VALUE;
     default:
-        OVS_NOT_REACHED();
+        return OFPERR_OFPGMFC_BAD_TYPE;
     }
 
     switch (group_cmd) {
@@ -1562,7 +1562,7 @@ parse_group_prop_ntr_selection_method(struct ofpbuf *payload,
                     "only allowed for add and delete group modifications");
         return OFPERR_OFPBPC_BAD_VALUE;
     default:
-        OVS_NOT_REACHED();
+        return OFPERR_OFPGMFC_BAD_COMMAND;
     }
 
     if (payload->size < sizeof *prop) {
-- 
2.16.1