ofproto: Fix for ovs-vswitchd crash on flow-mod with unsupported action

Problem Description:
The ovs-vswitchd is crashing while invoking flow-mod with upsupported
action(Tested with ovs2.10.1)

Steps to recreate:
Step 1) Create a flow
ovs-ofctl add-flow switch1
priority=228,dl_type=0x0800,dl_vlan="600",in_port=25,actions=output:ALL
This step is successful.

Step 2) Invoke flow-mod with incorrect contents.
ovs-ofctl mod-flows switch1
priority=228,dl_type=0x0800,dl_vlan="600",in_port=25,actions=output:ALL,mod_vlan_vid:50,mod_vlan_pcp=6,mod_nw_tos=16

In the above example, the ofproto provider I have, will return error for
rule_construct as set_fields come after Output.

However the OVS is ignoring the error (The return value of add_flow_init
is ignored in modify_flow_init_strict) and eventually the ovs-vswitched
crashes.

Crash backtrace:
-----------------------

Thread 1 "ovs-vswitchd" received signal SIGSEGV, Segmentation fault.

 0x00007f6a06e785fb in modify_flows_start__ (
   ofproto=ofproto@entry=0x55b289cecc28, ofm=ofm@entry=0x7ffdf7d57b70)
     at ofproto/ofproto.c:5402
 5402    in ofproto/ofproto.c
 (gdb) bt
 #0  0x00007f6a06e785fb in modify_flows_start__ (
   ofproto=ofproto@entry=0x55b289cecc28, ofm=ofm@entry=0x7ffdf7d57b70)
    at ofproto/ofproto.c:5402
 #1  0x00007f6a06e790db in modify_flows_start_loose (ofm=0x7ffdf7d57b70,
    ofproto=0x55b289cecc28) at ofproto/ofproto.c:5443
 #2  ofproto_flow_mod_start (ofproto=ofproto@entry=0x55b289cecc28,
     ofm=ofm@entry=0x7ffdf7d57b70) at ofproto/ofproto.c:7672
 #3  0x00007f6a06e79164 in handle_flow_mod__ (
    ofproto=ofproto@entry=0x55b289cecc28, fm=fm@entry=0x7ffdf7d57d20,
    req=req@entry=0x7ffdf7d57cd0) at ofproto/ofproto.c:5858
 #4  0x00007f6a06e792c2 in handle_flow_mod (ofconn=ofconn@entry
 =0x55b289d528c0,
oh=oh@entry=0x55b289d5a410) at ofproto/ofproto.c:5835
 #5  0x00007f6a06e7a173 in handle_openflow__ (msg=0x55b289d351d0,
    ofconn=0x55b289d528c0) at ofproto/ofproto.c:8127
 #6  handle_openflow (ofconn=0x55b289d528c0, ofp_msg=0x55b289d351d0)
  at ofproto/ofproto.c:8296
 #7  0x00007f6a06e6a013 in ofconn_run (
  handle_openflow=0x7f6a06e796f0 <handle_openflow>,
 ofconn=0x55b289d528c0)
 at ofproto/connmgr.c:1446
 #8  connmgr_run (mgr=0x55b289d14fe0,
 handle_openflow=handle_openflow@entry=0x7f6a06e796f0
handle_openflow>)
at ofproto/connmgr.c:365

With this fix, OVS does not crash.

Signed-off-by: Parameswaran Krishnamurthy <parkrish@gmail.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 40949eec933e06d2ed7c8ebdfef8bb6101f73e4c..40780e2766ab4315eb454ea6d80813481ca8bd29 100644 (file)
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -5652,9 +5652,7 @@ modify_flows_init_loose(struct ofproto *ofproto,
                              (fm->flags & OFPUTIL_FF_NO_READONLY) != 0);
     /* Must create a new flow in advance for the case that no matches are
      * found.  Also used for template for multiple modified flows. */
-    add_flow_init(ofproto, ofm, fm);
-
-    return 0;
+    return add_flow_init(ofproto, ofm, fm);
 }
 
 /* Implements OFPFC_MODIFY.  Returns 0 on success or an OpenFlow error code on
@@ -5737,9 +5735,7 @@ modify_flow_init_strict(struct ofproto *ofproto OVS_UNUSED,
                              (fm->flags & OFPUTIL_FF_NO_READONLY) != 0);
     /* Must create a new flow in advance for the case that no matches are
      * found.  Also used for template for multiple modified flows. */
-    add_flow_init(ofproto, ofm, fm);
-
-    return 0;
+    return add_flow_init(ofproto, ofm, fm);
 }
 
 /* Implements OFPFC_MODIFY_STRICT.  Returns 0 on success or an OpenFlow error