mobile-shell / mobile-shell/mosh

mosh crashes with -6 IPv6

Open
#1,302 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
C++
Stars
14.5k
Forks
865
PR merge metrics
No merged PRs in 30d

Description

The 1.3.2 version that comes with Ubuntu 22.04 started crashing on AAAA-records today, maybe the libc and friends update that came today?

I cloned this repo, and version 1.4.0 doesn't crash if there's an AAAA-record in DNS. It does crash however exactly in the same way as 1.3.2 when using the -6 flag.

 $ ./mosh -6 $host
Use of uninitialized value $addr_string in concatenation (.) or string at ./mosh line 283.
Use of uninitialized value $err in concatenation (.) or string at ./mosh line 283.
./mosh: Could not connect to (redacted), last tried : 
kex_exchange_identification: Connection closed by remote host
Connection closed by UNKNOWN port 65535
./mosh: Did not find remote IP address (is SSH ProxyCommand disabled?).

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Reproduce the failure on Ubuntu 22.04 with ./mosh -6 $host and inspect ./mosh around line 283, where the uninitialized values are reported. Compare this path with connecting to the same host through its AAAA record without -6. Done means the -6 connection no longer crashes and reports a usable remote address.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp, ubuntu
Domain
networking
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
30/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.