database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-08-24 09:27:52 +03:00
Code Activity

Don't read fields of a misaligned ExpandedObjectHeader or AnyArrayType.

Browse Source 
UBSan complains about this.  Instead, cast to a suitable type requiring
only 4-byte alignment.  DatumGetAnyArrayP() already assumes one can cast
between AnyArrayType and ArrayType, so this doesn't introduce a new
assumption.  Back-patch to 9.5, where AnyArrayType was introduced.

Reviewed by Tom Lane.

Discussion: https://postgr.es/m/20190629210334.GA1244217@rfd.leadboat.com
This commit is contained in:
Noah Misch
2019-06-30 17:34:17 -07:00
parent 4a36c77156
commit b664b187d7
4 changed files with 17 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
src/include/utils/array.h
View File

@@ -153,7 +153,10 @@ typedef struct ExpandedArrayHeader
/*
* Functions that can handle either a "flat" varlena array or an expanded
* array use this union to work with their input.
* array use this union to work with their input. Don't refer to "flt";
* instead, cast to ArrayType. This struct nominally requires 8-byte
* alignment on 64-bit, but it's often used for an ArrayType having 4-byte
* alignment. UBSan complains about referencing "flt" in such cases.
*/
typedef union AnyArrayType
{
@@ -307,17 +310,21 @@ typedef struct ArrayIteratorData *ArrayIterator;
* Macros for working with AnyArrayType inputs. Beware multiple references!
*/
#define AARR_NDIM(a) \
(VARATT_IS_EXPANDED_HEADER(a) ? (a)->xpn.ndims : ARR_NDIM(&(a)->flt))
(VARATT_IS_EXPANDED_HEADER(a) ? \
(a)->xpn.ndims : ARR_NDIM((ArrayType *) (a)))
#define AARR_HASNULL(a) \
(VARATT_IS_EXPANDED_HEADER(a) ? \
((a)->xpn.dvalues != NULL ? (a)->xpn.dnulls != NULL : ARR_HASNULL((a)->xpn.fvalue)) : \
ARR_HASNULL(&(a)->flt))
ARR_HASNULL((ArrayType *) (a)))
#define AARR_ELEMTYPE(a) \
(VARATT_IS_EXPANDED_HEADER(a) ? (a)->xpn.element_type : ARR_ELEMTYPE(&(a)->flt))
(VARATT_IS_EXPANDED_HEADER(a) ? \
(a)->xpn.element_type : ARR_ELEMTYPE((ArrayType *) (a)))
#define AARR_DIMS(a) \
(VARATT_IS_EXPANDED_HEADER(a) ? (a)->xpn.dims : ARR_DIMS(&(a)->flt))
(VARATT_IS_EXPANDED_HEADER(a) ? \
(a)->xpn.dims : ARR_DIMS((ArrayType *) (a)))
#define AARR_LBOUND(a) \
(VARATT_IS_EXPANDED_HEADER(a) ? (a)->xpn.lbound : ARR_LBOUND(&(a)->flt))
(VARATT_IS_EXPANDED_HEADER(a) ? \
(a)->xpn.lbound : ARR_LBOUND((ArrayType *) (a)))
/*