IPv6 address parsing doesn't limit buffer size

[sethmlarson]

Bug report

Bug description:

IPv6 addresses have a maximum length (8 colon-separated parts) but the current implementation doesn't limit the length. Similar issue to django/django@ca2be77

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-128840: Limit the number of parts in IPv6 address parsing #128841
• [3.14] gh-128840: Limit the number of parts in IPv6 address parsing (GH-128841) #134610
• [3.13] gh-128840: Limit the number of parts in IPv6 address parsing (GH-128841) #134611
• [3.12] gh-128840: Limit the number of parts in IPv6 address parsing (GH-128841) #134612
• [3.11] gh-128840: Limit the number of parts in IPv6 address parsing (GH-128841) #134613
• [3.10] gh-128840: Limit the number of parts in IPv6 address parsing (GH-128841) #134614
• [3.9] gh-128840: Limit the number of parts in IPv6 address parsing (GH-128841) #134615
• gh-128840: Fix parsing long IPv6 addresses with embedded IPv4 address #134836
• [3.14] gh-128840: Fix parsing long IPv6 addresses with embedded IPv4 address (GH-134836) #134845
• [3.13] gh-128840: Fix parsing long IPv6 addresses with embedded IPv4 address (GH-134836) #134846
• [3.12] gh-128840: Fix parsing long IPv6 addresses with embedded IPv4 address (GH-134836) #134847
• [3.10] gh-128840: Fix parsing long IPv6 addresses with embedded IPv4 address (GH-134836) #135089
• [3.9] gh-128840: Fix parsing long IPv6 addresses with embedded IPv4 address (GH-134836) #135090
• [3.11] gh-128840: Fix parsing long IPv6 addresses with embedded IPv4 address (GH-134836) #135091

[serhiy-storchaka]

I do not think this is a security issue.