valyala/fasthttp

It is not safe to read all stream body to memory without a max size limit.

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#1765 opened on Apr 23, 2024

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help wanted

Description

https://github.com/valyala/fasthttp/blob/57b9352ad1cc93a0aaaa72b2130e03ace8a5b118/http.go#L427 I think it would be safe to stop reading the request body into memory and return an error when it exceeds the maximum request body size. Otherwise, it may lead to an out-of-memory (OOM) error when the request body is too large.

Contributor guide

Tech stack
go
Domain
backendsecurity
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Go basicsHTTP server internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
The issue points to line 427 in http.go where the entire request body is read into memory without a size limit. To fix, add a check for a maximum request body size before reading, preferably using a configurable limit (e.g., MaxRequestBodySize). When exceeded, the read should stop and return an error, likely with a 413 status code. Ensure integration with the existing fasthttp request handling pipeline and consider any existing size settings.