Avoid platform-dependent infinite loop in pg_dump.

If malloc(0) returns NULL, the binary search in findSecLabels() will
probably go into an infinite loop when there are no security labels,
because NULL-1 is greater than NULL after wraparound.

(We've seen this pathology before ... I wonder whether there's a way to
detect the class of bugs automatically?)

Diagnosis and patch by Steve Singer, cosmetic adjustments by me
This commit is contained in:
Tom Lane 2011-11-10 16:08:14 -05:00
parent 409b8c75ba
commit cf22e851b6

View File

@ -645,9 +645,10 @@ main(int argc, char **argv)
do_sql_command(g_conn, "SET quote_all_identifiers = true");
/*
* Disables security label support if server version < v9.1.x
* Disable security label support if server version < v9.1.x (prevents
* access to nonexistent pg_seclabel catalog)
*/
if (!no_security_labels && g_fout->remoteVersion < 90100)
if (g_fout->remoteVersion < 90100)
no_security_labels = 1;
/*
@ -11993,6 +11994,12 @@ findSecLabels(Archive *fout, Oid classoid, Oid objoid, SecLabelItem **items)
if (nlabels < 0)
nlabels = collectSecLabels(fout, &labels);
if (nlabels <= 0) /* no labels, so no match is possible */
{
*items = NULL;
return 0;
}
/*
* Do binary search to find some item matching the object.
*/