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authorTom Lane <tgl@sss.pgh.pa.us>2022-07-31 13:43:17 -0400
committerTom Lane <tgl@sss.pgh.pa.us>2022-07-31 13:43:17 -0400
commitd386b75df553b11ba20707b2f0a74215bb9c120b (patch)
tree615942a56cb53885e2e3e6647088fdf00862d866
parente65f94982ed32d87daf53fb4d4067b2fe4a4df90 (diff)
downloadpostgresql-d386b75df553b11ba20707b2f0a74215bb9c120b.tar.gz
postgresql-d386b75df553b11ba20707b2f0a74215bb9c120b.zip
Fix trim_array() for zero-dimensional array argument.
The code tried to access ARR_DIMS(v)[0] and ARR_LBOUND(v)[0] whether or not those values exist. This made the range check on the "n" argument unstable --- it might or might not fail, and if it did it would report garbage for the allowed upper limit. These bogus accesses would probably annoy Valgrind, and if you were very unlucky even lead to SIGSEGV. Report and fix by Martin Kalcher. Back-patch to v14 where this function was added. Discussion: https://postgr.es/m/baaeb413-b8a8-4656-5757-ef347e5ec11f@aboutsource.net
-rw-r--r--src/backend/utils/adt/arrayfuncs.c9
-rw-r--r--src/test/regress/expected/arrays.out2
-rw-r--r--src/test/regress/sql/arrays.sql1
3 files changed, 9 insertions, 3 deletions
diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index 2570e5e6301..882bcdceca3 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -6685,7 +6685,7 @@ trim_array(PG_FUNCTION_ARGS)
{
ArrayType *v = PG_GETARG_ARRAYTYPE_P(0);
int n = PG_GETARG_INT32(1);
- int array_length = ARR_DIMS(v)[0];
+ int array_length = (ARR_NDIM(v) > 0) ? ARR_DIMS(v)[0] : 0;
int16 elmlen;
bool elmbyval;
char elmalign;
@@ -6705,8 +6705,11 @@ trim_array(PG_FUNCTION_ARGS)
/* Set all the bounds as unprovided except the first upper bound */
memset(lowerProvided, false, sizeof(lowerProvided));
memset(upperProvided, false, sizeof(upperProvided));
- upper[0] = ARR_LBOUND(v)[0] + array_length - n - 1;
- upperProvided[0] = true;
+ if (ARR_NDIM(v) > 0)
+ {
+ upper[0] = ARR_LBOUND(v)[0] + array_length - n - 1;
+ upperProvided[0] = true;
+ }
/* Fetch the needed information about the element type */
get_typlenbyvalalign(ARR_ELEMTYPE(v), &elmlen, &elmbyval, &elmalign);
diff --git a/src/test/regress/expected/arrays.out b/src/test/regress/expected/arrays.out
index ce6f3a65f97..97920f38c21 100644
--- a/src/test/regress/expected/arrays.out
+++ b/src/test/regress/expected/arrays.out
@@ -2445,3 +2445,5 @@ SELECT trim_array(ARRAY[1, 2, 3], -1); -- fail
ERROR: number of elements to trim must be between 0 and 3
SELECT trim_array(ARRAY[1, 2, 3], 10); -- fail
ERROR: number of elements to trim must be between 0 and 3
+SELECT trim_array(ARRAY[]::int[], 1); -- fail
+ERROR: number of elements to trim must be between 0 and 0
diff --git a/src/test/regress/sql/arrays.sql b/src/test/regress/sql/arrays.sql
index f774faf8568..791af5c0ce1 100644
--- a/src/test/regress/sql/arrays.sql
+++ b/src/test/regress/sql/arrays.sql
@@ -754,3 +754,4 @@ FROM
SELECT trim_array(ARRAY[1, 2, 3], -1); -- fail
SELECT trim_array(ARRAY[1, 2, 3], 10); -- fail
+SELECT trim_array(ARRAY[]::int[], 1); -- fail