svn commit: r234163 - head/sys/net
Andrew Thompson
thompsa at FreeBSD.org
Thu Apr 12 01:07:18 UTC 2012
Author: thompsa
Date: Thu Apr 12 01:07:17 2012
New Revision: 234163
URL: http://svn.freebsd.org/changeset/base/234163
Log:
Set the proto to LAGG_PROTO_NONE before calling the detach routine so packets
are discarded, this is an issue because lacp drops the lock which may allow
network threads to access freed memory. Expand the lock coverage so the
detach/attach happen atomically.
Submitted by: Andrew Boyer (earlier version)
Modified:
head/sys/net/if_lagg.c
Modified: head/sys/net/if_lagg.c
==============================================================================
--- head/sys/net/if_lagg.c Thu Apr 12 00:59:30 2012 (r234162)
+++ head/sys/net/if_lagg.c Thu Apr 12 01:07:17 2012 (r234163)
@@ -950,11 +950,11 @@ lagg_ioctl(struct ifnet *ifp, u_long cmd
error = EPROTONOSUPPORT;
break;
}
+ LAGG_WLOCK(sc);
if (sc->sc_proto != LAGG_PROTO_NONE) {
- LAGG_WLOCK(sc);
- error = sc->sc_detach(sc);
- /* Reset protocol and pointers */
+ /* Reset protocol first in case detach unlocks */
sc->sc_proto = LAGG_PROTO_NONE;
+ error = sc->sc_detach(sc);
sc->sc_detach = NULL;
sc->sc_start = NULL;
sc->sc_input = NULL;
@@ -966,10 +966,14 @@ lagg_ioctl(struct ifnet *ifp, u_long cmd
sc->sc_lladdr = NULL;
sc->sc_req = NULL;
sc->sc_portreq = NULL;
- LAGG_WUNLOCK(sc);
+ } else if (sc->sc_input != NULL) {
+ /* Still detaching */
+ error = EBUSY;
}
- if (error != 0)
+ if (error != 0) {
+ LAGG_WUNLOCK(sc);
break;
+ }
for (int i = 0; i < (sizeof(lagg_protos) /
sizeof(lagg_protos[0])); i++) {
if (lagg_protos[i].ti_proto == ra->ra_proto) {
@@ -977,7 +981,6 @@ lagg_ioctl(struct ifnet *ifp, u_long cmd
printf("%s: using proto %u\n",
sc->sc_ifname,
lagg_protos[i].ti_proto);
- LAGG_WLOCK(sc);
sc->sc_proto = lagg_protos[i].ti_proto;
if (sc->sc_proto != LAGG_PROTO_NONE)
error = lagg_protos[i].ti_attach(sc);
@@ -985,6 +988,7 @@ lagg_ioctl(struct ifnet *ifp, u_long cmd
return (error);
}
}
+ LAGG_WUNLOCK(sc);
error = EPROTONOSUPPORT;
break;
case SIOCGLAGGFLAGS:
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