Bug #20989: Segmentation fault in Ripper when lexing `/#{"\xcd"}/`

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [x86_64-linux]
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: REQUIRED

[Earlopain (Earlopain _)]

When I paste this code snippet into irb, I get a segfault: /#{"\xcd"}/. Current master (https://github.com/ruby/ruby/commit/adbbc9109ee71848204b5168a7c1bf604849e5fa) also fails.

Here is a simple reproduction, I attached the full bug as an attachment:

require "ripper"

lexer = Ripper::Lexer.new('/#{"\xcd"}/', '-', 0)
lexer.scan.each
# => /home/earlopain/.rbenv/versions/3.4.1/lib/ruby/3.4.0/ripper/lexer.rb:177: [BUG] Segmentation fault at 0x0000000000000008
# => ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [x86_64-linux]

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|fb18bb183c24ca82b8f114ed090d62bd69b5df84.

---

[Bug #20989] Ripper: Pass compile_error

For the universal parser, rb_parser_reg_fragment_check function is
shared between the parser and ripper. However parser_params struct
is partially different, and compile_error function depends on that
part indirectly.

[nobu (Nobuyoshi Nakada)]

• Backport changed from 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN to 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: REQUIRED

0ccc765 may be needed to backport to all versions.