Improve failure detection with array parsing in pg_dump

Similarly to 3636efa, the checks done in pg_dump when parsing array
values from catalogs have been too lax.  Under memory pressure, it could
be possible, though very unlikely, to finish with dumps that miss some
data like:
- Statistics for indexes
- Run-time configuration of functions
- Configuration of extensions
- Publication list for a subscription

No backpatch is done as this is not going to be a problem in practice.
For example, if an OOM causes an array parsing to fail, a follow-up code
path of pg_dump would most likely complain with an allocation failure
due to the memory pressure.

Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/20201111061319.GE2276@paquier.xyz

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index c68db75b97d03bbccad9d78824dea0eba9cd3935..dc1d41dd8d2380477096567bc9fc3bbd0b8e319f 100644 (file)
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4357,13 +4357,7 @@ dumpSubscription(Archive *fout, SubscriptionInfo *subinfo)
 
    /* Build list of quoted publications and append them to query. */
    if (!parsePGArray(subinfo->subpublications, &pubnames, &npubnames))
-   {
-       pg_log_warning("could not parse subpublications array");
-       if (pubnames)
-           free(pubnames);
-       pubnames = NULL;
-       npubnames = 0;
-   }
+       fatal("could not parse subpublications array");
 
    publications = createPQExpBuffer();
    for (i = 0; i < npubnames; i++)
@@ -12128,13 +12122,12 @@ dumpFunc(Archive *fout, FuncInfo *finfo)
    if (proconfig && *proconfig)
    {
        if (!parsePGArray(proconfig, &configitems, &nconfigitems))
-       {
-           pg_log_warning("could not parse proconfig array");
-           if (configitems)
-               free(configitems);
-           configitems = NULL;
-           nconfigitems = 0;
-       }
+           fatal("could not parse proconfig array");
+   }
+   else
+   {
+       configitems = NULL;
+       nconfigitems = 0;
    }
 
    if (funcargs)
@@ -16453,8 +16446,8 @@ dumpIndex(Archive *fout, IndxInfo *indxinfo)
        char       *indstatvals = indxinfo->indstatvals;
        char      **indstatcolsarray = NULL;
        char      **indstatvalsarray = NULL;
-       int         nstatcols;
-       int         nstatvals;
+       int         nstatcols = 0;
+       int         nstatvals = 0;
 
        if (dopt->binary_upgrade)
            binary_upgrade_set_pg_class_oids(fout, q,
@@ -16483,12 +16476,17 @@ dumpIndex(Archive *fout, IndxInfo *indxinfo)
         * If the index has any statistics on some of its columns, generate
         * the associated ALTER INDEX queries.
         */
-       if (parsePGArray(indstatcols, &indstatcolsarray, &nstatcols) &&
-           parsePGArray(indstatvals, &indstatvalsarray, &nstatvals) &&
-           nstatcols == nstatvals)
+       if (strlen(indstatcols) != 0 || strlen(indstatvals) != 0)
        {
            int         j;
 
+           if (!parsePGArray(indstatcols, &indstatcolsarray, &nstatcols))
+               fatal("could not parse index statistic columns");
+           if (!parsePGArray(indstatvals, &indstatvalsarray, &nstatvals))
+               fatal("could not parse index statistic values");
+           if (nstatcols != nstatvals)
+               fatal("mismatched number of columns and values for index stats");
+
            for (j = 0; j < nstatcols; j++)
            {
                appendPQExpBuffer(q, "ALTER INDEX %s ", qqindxname);
@@ -17938,15 +17936,20 @@ processExtensionTables(Archive *fout, ExtensionInfo extinfo[],
        char       *extcondition = curext->extcondition;
        char      **extconfigarray = NULL;
        char      **extconditionarray = NULL;
-       int         nconfigitems;
-       int         nconditionitems;
+       int         nconfigitems = 0;
+       int         nconditionitems = 0;
 
-       if (parsePGArray(extconfig, &extconfigarray, &nconfigitems) &&
-           parsePGArray(extcondition, &extconditionarray, &nconditionitems) &&
-           nconfigitems == nconditionitems)
+       if (strlen(extconfig) != 0 || strlen(extcondition) != 0)
        {
            int         j;
 
+           if (!parsePGArray(extconfig, &extconfigarray, &nconfigitems))
+               fatal("could not parse extension configuration array");
+           if (!parsePGArray(extcondition, &extconditionarray, &nconditionitems))
+               fatal("could not parse extension condition array");
+           if (nconfigitems != nconditionitems)
+               fatal("mismatched number of configurations and conditions for extension");
+
            for (j = 0; j < nconfigitems; j++)
            {
                TableInfo  *configtbl;