From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 7 Jan 2024 20:19:50 +0000 (-0500)
Subject: Fix integer-overflow problem in intarray's g_int_decompress().
X-Git-Tag: REL_12_18~32
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=1c7443521f856dfb5f6731ff6fc0865a67a29f14;p=postgresql.git

Fix integer-overflow problem in intarray's g_int_decompress().

An array element equal to INT_MAX gave this code indigestion,
causing an infinite loop that surely ended in SIGSEGV.  We fixed
some nearby problems awhile ago (cf 757c5182f) but missed this.

Report and diagnosis by Alexander Lakhin (bug #18273); patch by me

Discussion: https://postgr.es/m/18273-9a832d1da122600c@postgresql.org
---

diff --git a/contrib/intarray/_int_gist.c b/contrib/intarray/_int_gist.c
index 1213c5250f8..62cd9ba9794 100644
--- a/contrib/intarray/_int_gist.c
+++ b/contrib/intarray/_int_gist.c
@@ -287,8 +287,7 @@ g_int_decompress(PG_FUNCTION_ARGS)
 	ArrayType  *in;
 	int			lenin;
 	int		   *din;
-	int			i,
-				j;
+	int			i;
 
 	in = DatumGetArrayTypeP(entry->key);
 
@@ -332,9 +331,12 @@ g_int_decompress(PG_FUNCTION_ARGS)
 	dr = ARRPTR(r);
 
 	for (i = 0; i < lenin; i += 2)
-		for (j = din[i]; j <= din[i + 1]; j++)
+	{
+		/* use int64 for j in case din[i + 1] is INT_MAX */
+		for (int64 j = din[i]; j <= din[i + 1]; j++)
 			if ((!i) || *(dr - 1) != j)
-				*dr++ = j;
+				*dr++ = (int) j;
+	}
 
 	if (in != (ArrayType *) DatumGetPointer(entry->key))
 		pfree(in);
diff --git a/contrib/intarray/data/test__int.data b/contrib/intarray/data/test__int.data
index b3903d0f33a..0a7fac3c087 100644
--- a/contrib/intarray/data/test__int.data
+++ b/contrib/intarray/data/test__int.data
@@ -6998,3 +6998,4 @@
 {173,208,229}
 {6,22,142,267,299}
 {22,122,173,245,293}
+{1,2,101,102,201,202,2147483647}
diff --git a/contrib/intarray/expected/_int.out b/contrib/intarray/expected/_int.out
index d6218df47f8..28ba5bdba99 100644
--- a/contrib/intarray/expected/_int.out
+++ b/contrib/intarray/expected/_int.out
@@ -464,13 +464,13 @@ SELECT count(*) from test__int WHERE a @@ '(20&23)|(50&68)';
 SELECT count(*) from test__int WHERE a @@ '20 | !21';
  count 
 -------
-  6566
+  6567
 (1 row)
 
 SELECT count(*) from test__int WHERE a @@ '!20 & !21';
  count 
 -------
-  6343
+  6344
 (1 row)
 
 SET enable_seqscan = off;  -- not all of these would use index by default
@@ -538,13 +538,13 @@ SELECT count(*) from test__int WHERE a @@ '(20&23)|(50&68)';
 SELECT count(*) from test__int WHERE a @@ '20 | !21';
  count 
 -------
-  6566
+  6567
 (1 row)
 
 SELECT count(*) from test__int WHERE a @@ '!20 & !21';
  count 
 -------
-  6343
+  6344
 (1 row)
 
 INSERT INTO test__int SELECT array(SELECT x FROM generate_series(1, 1001) x); -- should fail
@@ -614,13 +614,13 @@ SELECT count(*) from test__int WHERE a @@ '(20&23)|(50&68)';
 SELECT count(*) from test__int WHERE a @@ '20 | !21';
  count 
 -------
-  6566
+  6567
 (1 row)
 
 SELECT count(*) from test__int WHERE a @@ '!20 & !21';
  count 
 -------
-  6343
+  6344
 (1 row)
 
 DROP INDEX text_idx;
@@ -688,13 +688,13 @@ SELECT count(*) from test__int WHERE a @@ '(20&23)|(50&68)';
 SELECT count(*) from test__int WHERE a @@ '20 | !21';
  count 
 -------
-  6566
+  6567
 (1 row)
 
 SELECT count(*) from test__int WHERE a @@ '!20 & !21';
  count 
 -------
-  6343
+  6344
 (1 row)
 
 RESET enable_seqscan;