From 5a2967412f63f3b9390aa7b3af95e2fae0965ff8 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Mon, 4 Nov 2019 08:30:00 +0100
Subject: [PATCH] Catch invalid typlens in a couple of places
Rearrange the logic in record_image_cmp() and datum_image_eq() to
error out on unexpected typlens (either not supported there or
completely invalid due to corruption). Barring corruption, this is
not possible today but it seems more future-proof and robust to fix
this.
Reported-by: Peter Geoghegan <pg@bowt.ie>
---
src/backend/utils/adt/datum.c | 22 ++++++++++++----------
src/backend/utils/adt/rowtypes.c | 24 +++++++++++++-----------
2 files changed, 25 insertions(+), 21 deletions(-)
diff --git a/src/backend/utils/adt/datum.c b/src/backend/utils/adt/datum.c
index 81ea5a48e59..76bd7ee1aa0 100644
--- a/src/backend/utils/adt/datum.c
+++ b/src/backend/utils/adt/datum.c
@@ -265,7 +265,17 @@ datum_image_eq(Datum value1, Datum value2, bool typByVal, int typLen)
{
bool result = true;
- if (typLen == -1)
+ if (typByVal)
+ {
+ result = (value1 == value2);
+ }
+ else if (typLen > 0)
+ {
+ result = (memcmp(DatumGetPointer(value1),
+ DatumGetPointer(value2),
+ typLen) == 0);
+ }
+ else if (typLen == -1)
{
Size len1,
len2;
@@ -294,16 +304,8 @@ datum_image_eq(Datum value1, Datum value2, bool typByVal, int typLen)
pfree(arg2val);
}
}
- else if (typByVal)
- {
- result = (value1 == value2);
- }
else
- {
- result = (memcmp(DatumGetPointer(value1),
- DatumGetPointer(value2),
- typLen) == 0);
- }
+ elog(ERROR, "unexpected typLen: %d", typLen);
return result;
}
diff --git a/src/backend/utils/adt/rowtypes.c b/src/backend/utils/adt/rowtypes.c
index aa7ec8735c4..4d6cfc68b86 100644
--- a/src/backend/utils/adt/rowtypes.c
+++ b/src/backend/utils/adt/rowtypes.c
@@ -1443,7 +1443,18 @@ record_image_cmp(FunctionCallInfo fcinfo)
}
/* Compare the pair of elements */
- if (att1->attlen == -1)
+ if (att1->attbyval)
+ {
+ if (values1[i1] != values2[i2])
+ cmpresult = (values1[i1] < values2[i2]) ? -1 : 1;
+ }
+ else if (att1->attlen > 0)
+ {
+ cmpresult = memcmp(DatumGetPointer(values1[i1]),
+ DatumGetPointer(values2[i2]),
+ att1->attlen);
+ }
+ else if (att1->attlen == -1)
{
Size len1,
len2;
@@ -1466,17 +1477,8 @@ record_image_cmp(FunctionCallInfo fcinfo)
if ((Pointer) arg2val != (Pointer) values2[i2])
pfree(arg2val);
}
- else if (att1->attbyval)
- {
- if (values1[i1] != values2[i2])
- cmpresult = (values1[i1] < values2[i2]) ? -1 : 1;
- }
else
- {
- cmpresult = memcmp(DatumGetPointer(values1[i1]),
- DatumGetPointer(values2[i2]),
- att1->attlen);
- }
+ elog(ERROR, "unexpected attlen: %d", att1->attlen);
if (cmpresult < 0)
{
--
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