[PR #581] [MERGED] Pointer in compressed label should not point to a current Name #1529

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opened 2026-03-16 02:11:22 +03:00 by kerem · 0 comments

kerem commented

2026-03-16 02:11:22 +03:00

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📋 Pull Request Information

Original PR: https://github.com/hickory-dns/hickory-dns/pull/581
Author: @oherrala
Created: 10/10/2018
Status: ✅ Merged
Merged: 10/10/2018
Merged by: @bluejekyll

Base: master ← Head: fix-name-reading

📝 Commits (1)

c10e88d Pointer in compressed label should not point to a current Name

📊 Changes

1 file changed (+9 additions, -2 deletions)

View changed files

📝 proto/src/rr/domain/name.rs (+9 -2)

📄 Description

This PR is related to prior PR #578 and backport PR #579.

If a pointer points to a current name it will cause infinite loop in parsing. This PR fixes the verification that the label pointer can only point to offset prior to the current Name.

Consider for example Name with label "a" followed by pointer to prior label "a". This will read "a" until stack runs out. "a.a.a.a.a.a..."

RFC1035 section 4.1.4 states that

In this scheme, an entire domain name or a list of labels at the end of a domain name is replaced with a pointer to a prior occurance of the same name.

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/hickory-dns/hickory-dns/pull/581 **Author:** [@oherrala](https://github.com/oherrala) **Created:** 10/10/2018 **Status:** ✅ Merged **Merged:** 10/10/2018 **Merged by:** [@bluejekyll](https://github.com/bluejekyll) **Base:** `master` ← **Head:** `fix-name-reading` --- ### 📝 Commits (1) - [`c10e88d`](https://github.com/hickory-dns/hickory-dns/commit/c10e88d535ddcc9696cb82e52e8e5a48f55fbb73) Pointer in compressed label should not point to a current Name ### 📊 Changes **1 file changed** (+9 additions, -2 deletions) <details> <summary>View changed files</summary> 📝 `proto/src/rr/domain/name.rs` (+9 -2) </details> ### 📄 Description This PR is related to prior PR #578 and backport PR #579. If a pointer points to a current name it will cause infinite loop in parsing. This PR fixes the verification that the label pointer can only point to offset prior to the current Name. Consider for example Name with label "a" followed by pointer to prior label "a". This will read "a" until stack runs out. "a.a.a.a.a.a..." RFC1035 section 4.1.4 states that > In this scheme, an entire domain name or a list of labels at the end of a domain name is replaced with a pointer to a prior occurance of the same name. --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>