Mirror
/
cpython
mirror of https://github.com/python/cpython
4
1
Fork 0
Code Issues Releases Wiki Activity

GH-96569: Add two NULL checks to avoid undefined behavior. (GH-96585)

This commit is contained in:
Mark Shannon 2022-09-06 16:45:43 +01:00 committed by GitHub
parent cd0ff9bd14
commit 222f10ca2d
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 13 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
Include/internal/pycore_frame.h
View File

@ -190,11 +190,16 @@ _PyFrame_FastToLocalsWithError(_PyInterpreterFrame *frame);
void
_PyFrame_LocalsToFast(_PyInterpreterFrame *frame, int clear);
static inline bool
_PyThreadState_HasStackSpace(PyThreadState *tstate, int size)
{
return tstate->datastack_top + size < tstate->datastack_limit;
assert(
(tstate->datastack_top == NULL && tstate->datastack_limit == NULL)
||
(tstate->datastack_top != NULL && tstate->datastack_limit != NULL)
);
return tstate->datastack_top != NULL &&
size < tstate->datastack_limit - tstate->datastack_top;
}
extern _PyInterpreterFrame *

1
Misc/NEWS.d/next/Core and Builtins/2022-09-05-16-43-44.gh-issue-96569.9lmTCC.rst Normal file
View File

@ -0,0 +1 @@
Remove two cases of undefined behavoir, by adding NULL checks.

13
Python/pystate.c
View File

@ -2195,15 +2195,12 @@ _PyInterpreterFrame *
_PyThreadState_PushFrame(PyThreadState *tstate, size_t size)
{
assert(size < INT_MAX/sizeof(PyObject *));
PyObject **base = tstate->datastack_top;
PyObject **top = base + size;
if (top >= tstate->datastack_limit) {
base = push_chunk(tstate, (int)size);
if (_PyThreadState_HasStackSpace(tstate, (int)size)) {
_PyInterpreterFrame *res = (_PyInterpreterFrame *)tstate->datastack_top;
tstate->datastack_top += size;
return res;
}
else {
tstate->datastack_top = top;
}
return (_PyInterpreterFrame *)base;
return (_PyInterpreterFrame *)push_chunk(tstate, (int)size);
}
void