Merge pull request #8207 from commodo/18.06-CVE-2018-20406

[18.06] python3: fix [CVE-2018-20406]

lang/python/python3/Makefile

@@ -14,7 +14,7 @@ PYTHON_VERSION:=$(PYTHON3_VERSION)
 PYTHON_VERSION_MICRO:=$(PYTHON3_VERSION_MICRO)
 
 PKG_NAME:=python3
-PKG_RELEASE:=3
+PKG_RELEASE:=4
 PKG_VERSION:=$(PYTHON_VERSION).$(PYTHON_VERSION_MICRO)
 
 PKG_SOURCE:=Python-$(PKG_VERSION).tar.xz

lang/python/python3/patches/018-closes-bpo-34656-Avoid-relying-on-signed-overflow-in.patch

@@ -0,0 +1,206 @@
+From 71a9c65e74a70b6ed39adc4ba81d311ac1aa2acc Mon Sep 17 00:00:00 2001
+From: "Miss Islington (bot)"
+ <31488909+miss-islington@users.noreply.github.com>
+Date: Thu, 20 Sep 2018 19:00:37 -0700
+Subject: [PATCH] closes bpo-34656: Avoid relying on signed overflow in _pickle
+ memos. (GH-9261)
+
+(cherry picked from commit a4ae828ee416a66d8c7bf5ee71d653c2cc6a26dd)
+
+Co-authored-by: Benjamin Peterson <benjamin@python.org>
+---
+ Modules/_pickle.c | 62 +++++++++++++++++++++++------------------------
+ 1 file changed, 31 insertions(+), 31 deletions(-)
+
+diff --git a/Modules/_pickle.c b/Modules/_pickle.c
+index f5202f50c5..93bc1c6fee 100644
+--- a/Modules/_pickle.c
++++ b/Modules/_pickle.c
+@@ -596,9 +596,9 @@ typedef struct {
+ } PyMemoEntry;
+ 
+ typedef struct {
+-    Py_ssize_t mt_mask;
+-    Py_ssize_t mt_used;
+-    Py_ssize_t mt_allocated;
++    size_t mt_mask;
++    size_t mt_used;
++    size_t mt_allocated;
+     PyMemoEntry *mt_table;
+ } PyMemoTable;
+ 
+@@ -644,8 +644,8 @@ typedef struct UnpicklerObject {
+     /* The unpickler memo is just an array of PyObject *s. Using a dict
+        is unnecessary, since the keys are contiguous ints. */
+     PyObject **memo;
+-    Py_ssize_t memo_size;       /* Capacity of the memo array */
+-    Py_ssize_t memo_len;        /* Number of objects in the memo */
++    size_t memo_size;       /* Capacity of the memo array */
++    size_t memo_len;        /* Number of objects in the memo */
+ 
+     PyObject *pers_func;        /* persistent_load() method, can be NULL. */
+     PyObject *pers_func_self;   /* borrowed reference to self if pers_func
+@@ -731,7 +731,6 @@ PyMemoTable_New(void)
+ static PyMemoTable *
+ PyMemoTable_Copy(PyMemoTable *self)
+ {
+-    Py_ssize_t i;
+     PyMemoTable *new = PyMemoTable_New();
+     if (new == NULL)
+         return NULL;
+@@ -748,7 +747,7 @@ PyMemoTable_Copy(PyMemoTable *self)
+         PyErr_NoMemory();
+         return NULL;
+     }
+-    for (i = 0; i < self->mt_allocated; i++) {
++    for (size_t i = 0; i < self->mt_allocated; i++) {
+         Py_XINCREF(self->mt_table[i].me_key);
+     }
+     memcpy(new->mt_table, self->mt_table,
+@@ -794,7 +793,7 @@ _PyMemoTable_Lookup(PyMemoTable *self, PyObject *key)
+ {
+     size_t i;
+     size_t perturb;
+-    size_t mask = (size_t)self->mt_mask;
++    size_t mask = self->mt_mask;
+     PyMemoEntry *table = self->mt_table;
+     PyMemoEntry *entry;
+     Py_hash_t hash = (Py_hash_t)key >> 3;
+@@ -816,22 +815,24 @@ _PyMemoTable_Lookup(PyMemoTable *self, PyObject *key)
+ 
+ /* Returns -1 on failure, 0 on success. */
+ static int
+-_PyMemoTable_ResizeTable(PyMemoTable *self, Py_ssize_t min_size)
++_PyMemoTable_ResizeTable(PyMemoTable *self, size_t min_size)
+ {
+     PyMemoEntry *oldtable = NULL;
+     PyMemoEntry *oldentry, *newentry;
+-    Py_ssize_t new_size = MT_MINSIZE;
+-    Py_ssize_t to_process;
++    size_t new_size = MT_MINSIZE;
++    size_t to_process;
+ 
+     assert(min_size > 0);
+ 
+-    /* Find the smallest valid table size >= min_size. */
+-    while (new_size < min_size && new_size > 0)
+-        new_size <<= 1;
+-    if (new_size <= 0) {
++    if (min_size > PY_SSIZE_T_MAX) {
+         PyErr_NoMemory();
+         return -1;
+     }
++
++    /* Find the smallest valid table size >= min_size. */
++    while (new_size < min_size) {
++        new_size <<= 1;
++    }
+     /* new_size needs to be a power of two. */
+     assert((new_size & (new_size - 1)) == 0);
+ 
+@@ -904,10 +905,12 @@ PyMemoTable_Set(PyMemoTable *self, PyObject *key, Py_ssize_t value)
+      * Very large memo tables (over 50K items) use doubling instead.
+      * This may help applications with severe memory constraints.
+      */
+-    if (!(self->mt_used * 3 >= (self->mt_mask + 1) * 2))
++    if (SIZE_MAX / 3 >= self->mt_used && self->mt_used * 3 < self->mt_allocated * 2) {
+         return 0;
+-    return _PyMemoTable_ResizeTable(self,
+-        (self->mt_used > 50000 ? 2 : 4) * self->mt_used);
++    }
++    // self->mt_used is always < PY_SSIZE_T_MAX, so this can't overflow.
++    size_t desired_size = (self->mt_used > 50000 ? 2 : 4) * self->mt_used;
++    return _PyMemoTable_ResizeTable(self, desired_size);
+ }
+ 
+ #undef MT_MINSIZE
+@@ -1352,9 +1355,9 @@ _Unpickler_Readline(UnpicklerObject *self, char **result)
+ /* Returns -1 (with an exception set) on failure, 0 on success. The memo array
+    will be modified in place. */
+ static int
+-_Unpickler_ResizeMemoList(UnpicklerObject *self, Py_ssize_t new_size)
++_Unpickler_ResizeMemoList(UnpicklerObject *self, size_t new_size)
+ {
+-    Py_ssize_t i;
++    size_t i;
+ 
+     assert(new_size > self->memo_size);
+ 
+@@ -1373,9 +1376,9 @@ _Unpickler_ResizeMemoList(UnpicklerObject *self, Py_ssize_t new_size)
+ 
+ /* Returns NULL if idx is out of bounds. */
+ static PyObject *
+-_Unpickler_MemoGet(UnpicklerObject *self, Py_ssize_t idx)
++_Unpickler_MemoGet(UnpicklerObject *self, size_t idx)
+ {
+-    if (idx < 0 || idx >= self->memo_size)
++    if (idx >= self->memo_size)
+         return NULL;
+ 
+     return self->memo[idx];
+@@ -1384,7 +1387,7 @@ _Unpickler_MemoGet(UnpicklerObject *self, Py_ssize_t idx)
+ /* Returns -1 (with an exception set) on failure, 0 on success.
+    This takes its own reference to `value`. */
+ static int
+-_Unpickler_MemoPut(UnpicklerObject *self, Py_ssize_t idx, PyObject *value)
++_Unpickler_MemoPut(UnpicklerObject *self, size_t idx, PyObject *value)
+ {
+     PyObject *old_item;
+ 
+@@ -4328,14 +4331,13 @@ static PyObject *
+ _pickle_PicklerMemoProxy_copy_impl(PicklerMemoProxyObject *self)
+ /*[clinic end generated code: output=bb83a919d29225ef input=b73043485ac30b36]*/
+ {
+-    Py_ssize_t i;
+     PyMemoTable *memo;
+     PyObject *new_memo = PyDict_New();
+     if (new_memo == NULL)
+         return NULL;
+ 
+     memo = self->pickler->memo;
+-    for (i = 0; i < memo->mt_allocated; ++i) {
++    for (size_t i = 0; i < memo->mt_allocated; ++i) {
+         PyMemoEntry entry = memo->mt_table[i];
+         if (entry.me_key != NULL) {
+             int status;
+@@ -6764,7 +6766,7 @@ static PyObject *
+ _pickle_UnpicklerMemoProxy_copy_impl(UnpicklerMemoProxyObject *self)
+ /*[clinic end generated code: output=e12af7e9bc1e4c77 input=97769247ce032c1d]*/
+ {
+-    Py_ssize_t i;
++    size_t i;
+     PyObject *new_memo = PyDict_New();
+     if (new_memo == NULL)
+         return NULL;
+@@ -6915,8 +6917,7 @@ static int
+ Unpickler_set_memo(UnpicklerObject *self, PyObject *obj)
+ {
+     PyObject **new_memo;
+-    Py_ssize_t new_memo_size = 0;
+-    Py_ssize_t i;
++    size_t new_memo_size = 0;
+ 
+     if (obj == NULL) {
+         PyErr_SetString(PyExc_TypeError,
+@@ -6933,7 +6934,7 @@ Unpickler_set_memo(UnpicklerObject *self, PyObject *obj)
+         if (new_memo == NULL)
+             return -1;
+ 
+-        for (i = 0; i < new_memo_size; i++) {
++        for (size_t i = 0; i < new_memo_size; i++) {
+             Py_XINCREF(unpickler->memo[i]);
+             new_memo[i] = unpickler->memo[i];
+         }
+@@ -6981,8 +6982,7 @@ Unpickler_set_memo(UnpicklerObject *self, PyObject *obj)
+ 
+   error:
+     if (new_memo_size) {
+-        i = new_memo_size;
+-        while (--i >= 0) {
++        for (size_t i = new_memo_size - 1; i != SIZE_MAX; i--) {
+             Py_XDECREF(new_memo[i]);
+         }
+         PyMem_FREE(new_memo);
+-- 
+2.17.1
+