Re: [PATCH v5 0/3] Re: [PATCH v4 2/2] stdio-common: Fix buffer overflow in scanf %mc [BZ #34008]

Project / Subsystem

glibc / stdio-common

Date

2026-04-17

Proposer

Carlos O'Donell <[email protected]>

Source type

public_inbox

Consensus

Proposed

Sentiment

7/10

Technical tradeoffs

  • Combining the test and the fix simplifies bisecting.
  • A separate patch optimizes %ms expansion.

All attributes

project
glibc
subsystem
stdio-common
patch_id
discussion_id
[email protected]
source_type
public_inbox
title
Re: [PATCH v5 0/3] Re: [PATCH v4 2/2] stdio-common: Fix buffer overflow in scanf %mc [BZ #34008]
headline
stdio-common: Fix buffer overflow in scanf %mc [BZ #34008]
tldr
The scanf %mc format specifier had a buffer overflow; upstream requests that the fix and its regression test be combined into a single commit.
stakes
Fixes a security vulnerability.
proposer
Carlos O'Donell <[email protected]>
consensus
Proposed
outcome
proposed
sentiment_score
7
sentiment_rationale
The discussion is focused on code quality and bisectability, indicating a positive and constructive environment.
technical_tradeoffs
  • Combining the test and the fix simplifies bisecting.
  • A separate patch optimizes %ms expansion.
series_id
glibc:[patch v4 ] stdio-common: fix buffer overflow in scanf %mc [bz #34008]
series_role
cover
series_parts
[]
tags
  • security
  • stdio
  • scanf
  • buffer overflow
bugzilla_url
date
2026-04-17T00:00:00.000Z

Re: [PATCH v5 0/3] Re: [PATCH v4 2/2] stdio-common: Fix buffer overflow in scanf %mc [BZ #34008]

A patch series fixes a buffer overflow in the scanf %mc format specifier. The overflow occurs due to missing size validation when allocating memory. The patch adds a regression test and fixes the overflow. The patch author has been asked to combine the fix and the regression test into a single commit for bisectability.