mountd: Handle memory exhaustion in mountlist_list()

I'm about to replace inet_aton(3)/gethostbyaddr(3) with
host_pton()/host_canonname() in mountlist_list().

Since host_canonname() returns a string allocated with strdup(3)
instead of xstrdup(), mountlist_list() must now deal with memory
exhaustion properly.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/mountd/rmtab.c b/utils/mountd/rmtab.c
index 854d519808dd23f7861b4623b3407ae6b55a99bd..cd6abc8823c59f340181690c202d2017a4f8a178 100644 (file)
--- a/utils/mountd/rmtab.c
+++ b/utils/mountd/rmtab.c
@@ -16,7 +16,7 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <netdb.h>
-#include "xmalloc.h"
+
 #include "misc.h"
 #include "exportfs.h"
 #include "xio.h"
@@ -179,9 +179,9 @@ mountlist_freeall(mountlist list)
        while (list != NULL) {
                mountlist m = list;
                list = m->ml_next;
-               xfree(m->ml_hostname);
-               xfree(m->ml_directory);
-               xfree(m);
+               free(m->ml_hostname);
+               free(m->ml_directory);
+               free(m);
        }
 }
 
@@ -211,16 +211,32 @@ mountlist_list(void)
 
                setrmtabent("r");
                while ((rep = getrmtabent(1, NULL)) != NULL) {
-                       m = (mountlist) xmalloc(sizeof(*m));
+                       m = calloc(1, sizeof(*m));
+                       if (m == NULL) {
+                               mountlist_freeall(mlist);
+                               mlist = NULL;
+                               xlog(L_ERROR, "%s: memory allocation failed",
+                                               __func__);
+                               break;
+                       }
 
                        if (reverse_resolve &&
                           inet_aton((const char *) rep->r_client, &addr) &&
                           (he = gethostbyaddr(&addr, sizeof(addr), AF_INET)))
-                               m->ml_hostname = xstrdup(he->h_name);
+                               m->ml_hostname = strdup(he->h_name);
                        else
-                               m->ml_hostname = xstrdup(rep->r_client);
+                               m->ml_hostname = strdup(rep->r_client);
+
+                       m->ml_directory = strdup(rep->r_path);
+
+                       if (m->ml_hostname == NULL || m->ml_directory == NULL) {
+                               mountlist_freeall(mlist);
+                               mlist = NULL;
+                               xlog(L_ERROR, "%s: memory allocation failed",
+                                               __func__);
+                               break;
+                       }
 
-                       m->ml_directory = xstrdup(rep->r_path);
                        m->ml_next = mlist;
                        mlist = m;
                }