[multipathd] fix a segv in enable_group()

pp->mpp->pg should not be NULL when entering enable_group().
Failing update_multipath_strings() can  lead to such a situation.
So check its return value and abord early.

diff --git a/multipathd/main.c b/multipathd/main.c
index 548b2d1..f186d7f 100644 (file)
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -1131,7 +1131,7 @@ enable_group(struct path * pp)
         * we can safely return here, because upon map reload, all
         * PG will be enabled.
         */
-       if (!pp->pgindex)
+       if (!pp->mpp->pg || !pp->pgindex)
                return;
 
        pgp = VECTOR_SLOT(pp->mpp->pg, pp->pgindex - 1);
@@ -1263,7 +1263,9 @@ checkerloop (void *ap)
                                pp->checkint = conf->checkint;
 
                                if (newstate == PATH_DOWN ||
-                                   newstate == PATH_SHAKY) {
+                                   newstate == PATH_SHAKY ||
+                                   update_multipath_strings(pp->mpp,
+                                                            vecs->pathvec)) {
                                        /*
                                         * proactively fail path in the DM
                                         */
@@ -1283,13 +1285,7 @@ checkerloop (void *ap)
                                reinstate_path(pp);
 
                                /*
-                                * need to switch group ?
-                                */
-                               update_multipath_strings(pp->mpp,
-                                                        vecs->pathvec);
-
-                               /*
-                                * schedule defered failback
+                                * schedule [defered] failback
                                 */
                                if (pp->mpp->pgfailback > 0)
                                        pp->mpp->failback_tick =