Segmentation fault in running exec() with large expression size.

[xxm]

BPO	42715
Nosy	@stestagg
Superseder	bpo-42712: Segmentation fault in running ast.literal_eval() with large expression size.

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2020-12-26.01:41:01.525>
created_at = <Date 2020-12-22.10:20:37.379>
labels = ['interpreter-core', '3.8', '3.9', '3.10', '3.7', 'type-crash']
title = 'Segmentation fault in running exec() with large expression size.'
updated_at = <Date 2020-12-26.01:41:01.525>
user = 'https://bugs.python.org/xxm'

bugs.python.org fields:

activity = <Date 2020-12-26.01:41:01.525>
actor = 'terry.reedy'
assignee = 'none'
closed = True
closed_date = <Date 2020-12-26.01:41:01.525>
closer = 'terry.reedy'
components = ['Interpreter Core']
creation = <Date 2020-12-22.10:20:37.379>
creator = 'xxm'
dependencies = []
files = []
hgrepos = []
issue_num = 42715
keywords = []
message_count = 2.0
messages = ['383580', '383604']
nosy_count = 2.0
nosy_names = ['xxm', 'stestagg']
pr_nums = []
priority = 'normal'
resolution = 'duplicate'
stage = 'resolved'
status = 'closed'
superseder = '42712'
type = 'crash'
url = 'https://bugs.python.org/issue42715'
versions = ['Python 3.7', 'Python 3.8', 'Python 3.9', 'Python 3.10']

[xxm]

Calling function exec() with large size can cause a segmentation fault in Python 3.7 -3.10. Please check the following two examples. The example 1 works as expected, while the second one triggers segmentation fault on Python 3.7,3.8,3.9,3.10. The primary difference between these two examples lay on the value of "n".

Example 1:
=========================================

mylist = []
n = 100000
print(exec("mylist"+"+mylist"*n))

==========================================

The actual output: Recursion Error on Python 3.5-3.10 (as expected)

Example 2:
===================================

mylist = []
n = 1000000
print(exec("mylist"+"+mylist"*n))

===================================

The actual output: Recursive Error on Python 3.5, 3.6 (as expected), segmentation fault on Python 3.7, 3.8, 3.9, 3.10 (not as expected)

My system information:

> python3.10 -V
Python 3.10.0a2

> python3.9 -V
Python 3.9.0rc1

> python3.8 -V
Python 3.8.0

> python3.7 -V
Python 3.7.3

> python3.6 -V
Python 3.6.12

> uname -v
#73~16.04.1-Ubuntu

[stestagg]

As with the other issues, the underlying segfault is fixed in
PR: #23744. It does however raise a RecursionError:

RecursionError: maximum recursion depth exceeded during compilation

As per https://bugs.python.org/issue42609#msg382910, Serhiy implies that the new recursion error is probably expected and acceptable.