On Tue, Feb 16, 2021 at 1:06 PM Yifeng Sun <[email protected]> wrote: > > ovs-vswitchd could crash under these circumstances: > 1. When one bridge is being destroyed, ofproto_destroy() is called and > connmgr pointer of its ofproto struct is nullified. This ofproto struct is > deallocated through 'ovsrcu_postpone(ofproto_destroy_defer__, p);'. > 2. Before RCU enters quiesce state to actually free this ofproto struct, > revalidator thread calls udpif_revalidator(), which could handle > a learn flow and calls ofproto_flow_mod_learn(), it later calls > ofmonitor_report() and ofproto struct's connmgr pointer is accessed. > > The crash stack trace is shown below: > > 0 ofmonitor_report (mgr=0x0, rule=rule@entry=0x7fa4ac067c30, > event=event@entry=NXFME_ADDED, > reason=reason@entry=OFPRR_IDLE_TIMEOUT, abbrev_ofconn=0x0, abbrev_xid=0, > old_actions=old_actions@entry=0x0) > at ofproto/connmgr.c:2160 > 1 0x00007fa4d6803495 in add_flow_finish (ofproto=0x55d9075d4ab0, > ofm=<optimized out>, req=req@entry=0x0) > at ofproto/ofproto.c:5221 > 2 0x00007fa4d68036af in modify_flows_finish (req=0x0, ofm=0x7fa4980753f0, > ofproto=0x55d9075d4ab0) > at ofproto/ofproto.c:5823 > 3 ofproto_flow_mod_finish (ofproto=0x55d9075d4ab0, > ofm=ofm@entry=0x7fa4980753f0, req=req@entry=0x0) > at ofproto/ofproto.c:8088 > 4 0x00007fa4d680372d in ofproto_flow_mod_learn_finish > (ofm=ofm@entry=0x7fa4980753f0, > orig_ofproto=orig_ofproto@entry=0x0) at ofproto/ofproto.c:5439 > 5 0x00007fa4d68072f9 in ofproto_flow_mod_learn (ofm=0x7fa4980753f0, > keep_ref=keep_ref@entry=true, > limit=<optimized out>, below_limitp=below_limitp@entry=0x0) at > ofproto/ofproto.c:5499 > 6 0x00007fa4d6835d33 in xlate_push_stats_entry (entry=0x7fa498012448, > stats=stats@entry=0x7fa4d2701a10, > offloaded=offloaded@entry=false) at ofproto/ofproto-dpif-xlate-cache.c:127 > 7 0x00007fa4d6835e3a in xlate_push_stats (xcache=<optimized out>, > stats=stats@entry=0x7fa4d2701a10, > offloaded=offloaded@entry=false) at ofproto/ofproto-dpif-xlate-cache.c:181 > 8 0x00007fa4d6822046 in revalidate_ukey (udpif=udpif@entry=0x55d90760b240, > ukey=ukey@entry=0x7fa4b0191660, > stats=stats@entry=0x7fa4d2705118, > odp_actions=odp_actions@entry=0x7fa4d2701b50, > reval_seq=reval_seq@entry=5655486242, > recircs=recircs@entry=0x7fa4d2701b40, offloaded=false) > at ofproto/ofproto-dpif-upcall.c:2294 > 9 0x00007fa4d6825aee in revalidate (revalidator=0x55d90769dd00) at > ofproto/ofproto-dpif-upcall.c:2683 > 10 0x00007fa4d6825cf3 in udpif_revalidator (arg=0x55d90769dd00) at > ofproto/ofproto-dpif-upcall.c:936 > 11 0x00007fa4d6259c9f in ovsthread_wrapper (aux_=<optimized out>) at > lib/ovs-thread.c:423 > 12 0x00007fa4d582cea5 in start_thread () from /usr/lib64/libpthread.so.0 > 13 0x00007fa4d504b96d in clone () from /usr/lib64/libc.so.6 > > At the time of crash, the involved ofproto was already deallocated: > > (gdb) print *ofproto > $1 = ..., name = 0x55d907602820 "nsx-managed", ..., ports = {..., > one = 0x0, mask = 63, n = 0}, ..., connmgr = 0x0, ... > > This patch fixes it. > > VMware-BZ: #2700626 > Signed-off-by: Yifeng Sun <[email protected]> > ---
LGTM. Acked-by: Yi-Hung Wei <[email protected]> _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
