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author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2022-10-04 10:08:24 -0700 |
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committer | GitHub <noreply@github.com> | 2022-10-04 10:08:24 -0700 |
commit | f9ce9d4684cc293f40171af8fde253e4762baf9d (patch) | |
tree | ae03e83b33a40fc44636ae5d4d3a04f60f053470 | |
parent | 90620490c04b6894d5a3f4214ecf5a10b41d25ec (diff) | |
download | cpython-git-f9ce9d4684cc293f40171af8fde253e4762baf9d.tar.gz |
[3.8] gh-97616: list_resize() checks for integer overflow (GH-97617) (GH-97628)
gh-97616: list_resize() checks for integer overflow (GH-97617)
Fix multiplying a list by an integer (list *= int): detect the
integer overflow when the new allocated length is close to the
maximum size. Issue reported by Jordan Limor.
list_resize() now checks for integer overflow before multiplying the
new allocated length by the list item size (sizeof(PyObject*)).
(cherry picked from commit a5f092f3c469b674b8d9ccbd4e4377230c9ac7cf)
Co-authored-by: Victor Stinner <vstinner@python.org>
-rw-r--r-- | Lib/test/test_list.py | 13 | ||||
-rw-r--r-- | Misc/NEWS.d/next/Security/2022-09-28-17-09-37.gh-issue-97616.K1e3Xs.rst | 3 | ||||
-rw-r--r-- | Objects/listobject.c | 10 |
3 files changed, 24 insertions, 2 deletions
diff --git a/Lib/test/test_list.py b/Lib/test/test_list.py index 105ef650ee..75ecc70b0b 100644 --- a/Lib/test/test_list.py +++ b/Lib/test/test_list.py @@ -68,6 +68,19 @@ class ListTest(list_tests.CommonTest): self.assertRaises((MemoryError, OverflowError), mul, lst, n) self.assertRaises((MemoryError, OverflowError), imul, lst, n) + def test_list_resize_overflow(self): + # gh-97616: test new_allocated * sizeof(PyObject*) overflow + # check in list_resize() + lst = [0] * 65 + del lst[1:] + self.assertEqual(len(lst), 1) + + size = ((2 ** (tuple.__itemsize__ * 8) - 1) // 2) + with self.assertRaises((MemoryError, OverflowError)): + lst * size + with self.assertRaises((MemoryError, OverflowError)): + lst *= size + def test_repr_large(self): # Check the repr of large list objects def check(n): diff --git a/Misc/NEWS.d/next/Security/2022-09-28-17-09-37.gh-issue-97616.K1e3Xs.rst b/Misc/NEWS.d/next/Security/2022-09-28-17-09-37.gh-issue-97616.K1e3Xs.rst new file mode 100644 index 0000000000..721427fe64 --- /dev/null +++ b/Misc/NEWS.d/next/Security/2022-09-28-17-09-37.gh-issue-97616.K1e3Xs.rst @@ -0,0 +1,3 @@ +Fix multiplying a list by an integer (``list *= int``): detect the integer +overflow when the new allocated length is close to the maximum size. Issue +reported by Jordan Limor. Patch by Victor Stinner. diff --git a/Objects/listobject.c b/Objects/listobject.c index 30444089ff..473de9d2dd 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -66,8 +66,14 @@ list_resize(PyListObject *self, Py_ssize_t newsize) if (newsize == 0) new_allocated = 0; - num_allocated_bytes = new_allocated * sizeof(PyObject *); - items = (PyObject **)PyMem_Realloc(self->ob_item, num_allocated_bytes); + if (new_allocated <= (size_t)PY_SSIZE_T_MAX / sizeof(PyObject *)) { + num_allocated_bytes = new_allocated * sizeof(PyObject *); + items = (PyObject **)PyMem_Realloc(self->ob_item, num_allocated_bytes); + } + else { + // integer overflow + items = NULL; + } if (items == NULL) { PyErr_NoMemory(); return -1; |