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Issue #15144: Fix possible integer overflow when handling pointers as integer values, by using Py_uintptr_t instead of size_t. 

Patch by Serhiy Storchaka.
This commit is contained in:
Antoine Pitrou 2012-09-20 20:56:47 +02:00
parent 1c47222a25
commit ca8aa4acf6
11 changed files with 44 additions and 45 deletions
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9
Include/objimpl.h
View File

@ -181,12 +181,9 @@ PyAPI_FUNC(PyVarObject *) _PyObject_NewVar(PyTypeObject *, Py_ssize_t);
#endif
#define _PyObject_VAR_SIZE(typeobj, nitems) \
(size_t) \
( ( (typeobj)->tp_basicsize + \
(nitems)*(typeobj)->tp_itemsize + \
(SIZEOF_VOID_P - 1) \
) & ~(SIZEOF_VOID_P - 1) \
)
_Py_SIZE_ROUND_UP((typeobj)->tp_basicsize + \
(nitems)*(typeobj)->tp_itemsize, \
SIZEOF_VOID_P)
#define PyObject_NEW(type, typeobj) \
( (type *) PyObject_Init( \

14
Include/pymacro.h
View File

@ -52,4 +52,18 @@
#define PyDoc_STR(str) ""
#endif
/* Below "a" is a power of 2. */
/* Round down size "n" to be a multiple of "a". */
#define _Py_SIZE_ROUND_DOWN(n, a) ((size_t)(n) & ~(size_t)((a) - 1))
/* Round up size "n" to be a multiple of "a". */
#define _Py_SIZE_ROUND_UP(n, a) (((size_t)(n) + \
(size_t)((a) - 1)) & ~(size_t)((a) - 1))
/* Round pointer "p" down to the closest "a"-aligned address <= "p". */
#define _Py_ALIGN_DOWN(p, a) ((void *)((Py_uintptr_t)(p) & ~(Py_uintptr_t)((a) - 1)))
/* Round pointer "p" up to the closest "a"-aligned address >= "p". */
#define _Py_ALIGN_UP(p, a) ((void *)(((Py_uintptr_t)(p) + \
(Py_uintptr_t)((a) - 1)) & ~(Py_uintptr_t)((a) - 1)))
/* Check if pointer "p" is aligned to "a"-bytes boundary. */
#define _Py_IS_ALIGNED(p, a) (!((Py_uintptr_t)(p) & (Py_uintptr_t)((a) - 1)))
#endif /* Py_PYMACRO_H */

4
Misc/NEWS
View File

@ -10,6 +10,10 @@ What's New in Python 3.3.1
Core and Builtins
-----------------
- Issue #15144: Fix possible integer overflow when handling pointers as
integer values, by using Py_uintptr_t instead of size_t. Patch by
Serhiy Storchaka.
- Issue #15965: Explicitly cast AT_FDCWD as (int). Required on Solaris 10
(which defines AT_FDCWD as 0xffd19553), harmless on other platforms.

2
Modules/_elementtree.c
View File

@ -98,7 +98,7 @@ do { memory -= size; printf("%8d - %s\n", memory, comment); } while (0)
info. */
#define JOIN_GET(p) ((Py_uintptr_t) (p) & 1)
#define JOIN_SET(p, flag) ((void*) ((Py_uintptr_t) (JOIN_OBJ(p)) | (flag)))
#define JOIN_OBJ(p) ((PyObject*) ((Py_uintptr_t) (p) & ~1))
#define JOIN_OBJ(p) ((PyObject*) ((Py_uintptr_t) (p) & ~(Py_uintptr_t)1))
/* glue functions (see the init function for details) */
static PyObject* elementtree_parseerror_obj;

7
Objects/obmalloc.c
View File

@ -138,7 +138,6 @@ static int running_on_valgrind = -1;
*/
#define ALIGNMENT 8 /* must be 2^N */
#define ALIGNMENT_SHIFT 3
#define ALIGNMENT_MASK (ALIGNMENT - 1)
/* Return the number of bytes in size class I, as a uint. */
#define INDEX2SIZE(I) (((uint)(I) + 1) << ALIGNMENT_SHIFT)
@ -314,14 +313,12 @@ struct arena_object {
struct arena_object* prevarena;
};
#undef ROUNDUP
#define ROUNDUP(x) (((x) + ALIGNMENT_MASK) & ~ALIGNMENT_MASK)
#define POOL_OVERHEAD ROUNDUP(sizeof(struct pool_header))
#define POOL_OVERHEAD _Py_SIZE_ROUND_UP(sizeof(struct pool_header), ALIGNMENT)
#define DUMMY_SIZE_IDX 0xffff /* size class of newly cached pools */
/* Round pointer P down to the closest pool-aligned address <= P, as a poolp */
#define POOL_ADDR(P) ((poolp)((uptr)(P) & ~(uptr)POOL_SIZE_MASK))
#define POOL_ADDR(P) ((poolp)_Py_ALIGN_DOWN((P), POOL_SIZE))
/* Return total number of blocks in pool of size index I, as a uint. */
#define NUMBLOCKS(I) ((uint)(POOL_SIZE - POOL_OVERHEAD) / INDEX2SIZE(I))

14
Objects/stringlib/codecs.h
View File

@ -2,9 +2,6 @@
#if STRINGLIB_IS_UNICODE
/* Mask to check or force alignment of a pointer to C 'long' boundaries */
#define LONG_PTR_MASK (size_t) (SIZEOF_LONG - 1)
/* Mask to quickly check whether a C 'long' contains a
non-ASCII, UTF8-encoded char. */
#if (SIZEOF_LONG == 8)
@ -25,7 +22,7 @@ STRINGLIB(utf8_decode)(const char **inptr, const char *end,
{
Py_UCS4 ch;
const char *s = *inptr;
const char *aligned_end = (const char *) ((size_t) end & ~LONG_PTR_MASK);
const char *aligned_end = (const char *) _Py_ALIGN_DOWN(end, SIZEOF_LONG);
STRINGLIB_CHAR *p = dest + *outpos;
while (s < end) {
@ -39,7 +36,7 @@ STRINGLIB(utf8_decode)(const char **inptr, const char *end,
First, check if we can do an aligned read, as most CPUs have
a penalty for unaligned reads.
*/
if (!((size_t) s & LONG_PTR_MASK)) {
if (_Py_IS_ALIGNED(s, SIZEOF_LONG)) {
/* Help register allocation */
register const char *_s = s;
register STRINGLIB_CHAR *_p = p;
@ -453,7 +450,7 @@ STRINGLIB(utf16_decode)(const unsigned char **inptr, const unsigned char *e,
{
Py_UCS4 ch;
const unsigned char *aligned_end =
(const unsigned char *) ((size_t) e & ~LONG_PTR_MASK);
(const unsigned char *) _Py_ALIGN_DOWN(e, SIZEOF_LONG);
const unsigned char *q = *inptr;
STRINGLIB_CHAR *p = dest + *outpos;
/* Offsets from q for retrieving byte pairs in the right order. */
@ -468,7 +465,7 @@ STRINGLIB(utf16_decode)(const unsigned char **inptr, const unsigned char *e,
Py_UCS4 ch2;
/* First check for possible aligned read of a C 'long'. Unaligned
reads are more expensive, better to defer to another iteration. */
if (!((size_t) q & LONG_PTR_MASK)) {
if (_Py_IS_ALIGNED(q, SIZEOF_LONG)) {
/* Fast path for runs of in-range non-surrogate chars. */
register const unsigned char *_q = q;
while (_q < aligned_end) {
@ -565,7 +562,6 @@ IllegalSurrogate:
#undef FAST_CHAR_MASK
#undef STRIPPED_MASK
#undef SWAB
#undef LONG_PTR_MASK
Py_LOCAL_INLINE(void)
@ -588,7 +584,7 @@ STRINGLIB(utf16_encode)(unsigned short *out,
_PyUnicode_CONVERT_BYTES(STRINGLIB_CHAR, unsigned short, in, end, out);
# endif
} else {
const STRINGLIB_CHAR *unrolled_end = in + (len & ~ (Py_ssize_t) 3);
const STRINGLIB_CHAR *unrolled_end = in + _Py_SIZE_ROUND_DOWN(len, 4);
while (in < unrolled_end) {
out[0] = SWAB2(in[0]);
out[1] = SWAB2(in[1]);

3
Objects/stringlib/fastsearch.h
View File

@ -43,8 +43,7 @@ STRINGLIB(fastsearch_memchr_1char)(const STRINGLIB_CHAR* s, Py_ssize_t n,
#define DO_MEMCHR(memchr, s, needle, nchars) do { \
candidate = memchr((const void *) (s), (needle), (nchars) * sizeof(STRINGLIB_CHAR)); \
found = (const STRINGLIB_CHAR *) \
((Py_ssize_t) candidate & (~ ((Py_ssize_t) sizeof(STRINGLIB_CHAR) - 1))); \
found = (const STRINGLIB_CHAR *) _Py_ALIGN_DOWN(candidate, sizeof(STRINGLIB_CHAR)); \
} while (0)
if (mode == FAST_SEARCH) {

11
Objects/stringlib/find_max_char.h
View File

@ -2,9 +2,6 @@
#if STRINGLIB_IS_UNICODE
/* Mask to check or force alignment of a pointer to C 'long' boundaries */
#define LONG_PTR_MASK (size_t) (SIZEOF_LONG - 1)
/* Mask to quickly check whether a C 'long' contains a
non-ASCII, UTF8-encoded char. */
#if (SIZEOF_LONG == 8)
@ -21,10 +18,11 @@ Py_LOCAL_INLINE(Py_UCS4)
STRINGLIB(find_max_char)(const STRINGLIB_CHAR *begin, const STRINGLIB_CHAR *end)
{
const unsigned char *p = (const unsigned char *) begin;
const unsigned char *aligned_end = (const unsigned char *) ((size_t) end & ~LONG_PTR_MASK);
const unsigned char *aligned_end =
(const unsigned char *) _Py_ALIGN_DOWN(end, SIZEOF_LONG);
while (p < end) {
if (!((size_t) p & LONG_PTR_MASK)) {
if (_Py_IS_ALIGNED(p, SIZEOF_LONG)) {
/* Help register allocation */
register const unsigned char *_p = p;
while (_p < aligned_end) {
@ -43,7 +41,6 @@ STRINGLIB(find_max_char)(const STRINGLIB_CHAR *begin, const STRINGLIB_CHAR *end)
return 127;
}
#undef LONG_PTR_MASK
#undef ASCII_CHAR_MASK
#else /* STRINGLIB_SIZEOF_CHAR == 1 */
@ -72,7 +69,7 @@ STRINGLIB(find_max_char)(const STRINGLIB_CHAR *begin, const STRINGLIB_CHAR *end)
register Py_UCS4 mask;
Py_ssize_t n = end - begin;
const STRINGLIB_CHAR *p = begin;
const STRINGLIB_CHAR *unrolled_end = begin + (n & ~ (Py_ssize_t) 3);
const STRINGLIB_CHAR *unrolled_end = begin + _Py_SIZE_ROUND_DOWN(n, 4);
Py_UCS4 max_char;
max_char = MAX_CHAR_ASCII;

15
Objects/unicodeobject.c
View File

@ -159,7 +159,7 @@ extern "C" {
const from_type *_end = (end); \
Py_ssize_t n = (_end) - (_iter); \
const from_type *_unrolled_end = \
_iter + (n & ~ (Py_ssize_t) 3); \
_iter + _Py_SIZE_ROUND_DOWN(n, 4); \
while (_iter < (_unrolled_end)) { \
_to[0] = (to_type) _iter[0]; \
_to[1] = (to_type) _iter[1]; \
@ -4635,9 +4635,6 @@ PyUnicode_DecodeUTF8(const char *s,
#include "stringlib/codecs.h"
#include "stringlib/undef.h"
/* Mask to check or force alignment of a pointer to C 'long' boundaries */
#define LONG_PTR_MASK (size_t) (SIZEOF_LONG - 1)
/* Mask to quickly check whether a C 'long' contains a
non-ASCII, UTF8-encoded char. */
#if (SIZEOF_LONG == 8)
@ -4652,11 +4649,11 @@ static Py_ssize_t
ascii_decode(const char *start, const char *end, Py_UCS1 *dest)
{
const char *p = start;
const char *aligned_end = (const char *) ((size_t) end & ~LONG_PTR_MASK);
const char *aligned_end = (const char *) _Py_ALIGN_DOWN(end, SIZEOF_LONG);
#if SIZEOF_LONG <= SIZEOF_VOID_P
assert(!((size_t) dest & LONG_PTR_MASK));
if (!((size_t) p & LONG_PTR_MASK)) {
assert(_Py_IS_ALIGNED(dest, SIZEOF_LONG));
if (_Py_IS_ALIGNED(p, SIZEOF_LONG)) {
/* Fast path, see in STRINGLIB(utf8_decode) for
an explanation. */
/* Help register allocation */
@ -4682,7 +4679,7 @@ ascii_decode(const char *start, const char *end, Py_UCS1 *dest)
while (p < end) {
/* Fast path, see in STRINGLIB(utf8_decode) in stringlib/codecs.h
for an explanation. */
if (!((size_t) p & LONG_PTR_MASK)) {
if (_Py_IS_ALIGNED(p, SIZEOF_LONG)) {
/* Help register allocation */
register const char *_p = p;
while (_p < aligned_end) {
@ -5390,7 +5387,7 @@ _PyUnicode_EncodeUTF16(PyObject *str,
return NULL;
/* output buffer is 2-bytes aligned */
assert(((Py_uintptr_t)PyBytes_AS_STRING(v) & 1) == 0);
assert(_Py_IS_ALIGNED(PyBytes_AS_STRING(v), 2));
out = (unsigned short *)PyBytes_AS_STRING(v);
if (byteorder == 0)
*out++ = 0xFEFF;

2
Parser/node.c
View File

@ -71,7 +71,7 @@ fancy_roundup(int n)
* capacity. The code is tricky to avoid that.
*/
#define XXXROUNDUP(n) ((n) <= 1 ? (n) : \
(n) <= 128 ? (((n) + 3) & ~3) : \
(n) <= 128 ? _Py_SIZE_ROUND_UP((n), 4) : \
fancy_roundup(n))

8
Python/pyarena.c
View File

@ -12,8 +12,6 @@
#define DEFAULT_BLOCK_SIZE 8192
#define ALIGNMENT 8
#define ALIGNMENT_MASK (ALIGNMENT - 1)
#define ROUNDUP(x) (((x) + ALIGNMENT_MASK) & ~ALIGNMENT_MASK)
typedef struct _block {
/* Total number of bytes owned by this block available to pass out.
@ -85,8 +83,8 @@ block_new(size_t size)
b->ab_size = size;
b->ab_mem = (void *)(b + 1);
b->ab_next = NULL;
b->ab_offset = ROUNDUP((Py_uintptr_t)(b->ab_mem)) -
(Py_uintptr_t)(b->ab_mem);
b->ab_offset = (char *)_Py_ALIGN_UP(b->ab_mem, ALIGNMENT) -
(char *)(b->ab_mem);
return b;
}
@ -104,7 +102,7 @@ block_alloc(block *b, size_t size)
{
void *p;
assert(b);
size = ROUNDUP(size);
size = _Py_SIZE_ROUND_UP(size, ALIGNMENT);
if (b->ab_offset + size > b->ab_size) {
/* If we need to allocate more memory than will fit in
the default block, allocate a one-off block that is