Bug 2424192 - Latest update of passt breaks rootless network when ipv6 is disabled
Summary: Latest update of passt breaks rootless network when ipv6 is disabled
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: passt
Version: 42
Hardware: x86_64
OS: Linux
urgent
high
Target Milestone: ---
Assignee: Stefano Brivio
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-12-21 15:49 UTC by Iyan
Modified: 2025-12-31 01:09 UTC (History)
1 user (show)

Fixed In Version: passt-0^20251223.g2ba9fd5-1.fc43 passt-0^20251223.g2ba9fd5-1.fc42
Clone Of:
Environment:
Last Closed: 2025-12-31 00:50:50 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description Iyan 2025-12-21 15:49:46 UTC
After updating today `passt` and `passt-selinux` from `0^20250919.g623dbf6-1.fc42` to `0^20251215.gb40f5cd-1.fc42`, all my rootless containers failed to start.

These are the relevant errors:

```
Dec 21 07:14:44 tantiss pasta[2437]: Couldn't set IPv6 route(s) in guest: Operation not supported
Dec 21 07:14:44 tantiss pasta[2529]: Couldn't set IPv6 route(s) in guest: Operation not supported
Dec 21 07:14:44 tantiss systemd[1276]: Failed to start podman-compose - drand-mainnet rootless pod (podman-compose).
Dec 21 07:14:44 tantiss systemd[1276]: Failed to start podman-compose - drand-testnet rootless pod (podman-compose).
```

My host has ipv6 disabled via kernel using `ipv6.disable=1`, and the podman networks all have `"ipv6_enabled": false`. However, with this new version of passt, it seems like it still tries to setup an IPv6, of course fails to do so, and the containers are never started.

Downgrading to the previous version with `dnf downgrade passt` is a valid workaround.

Reproducible: Always

Steps to Reproduce:
1. dnf update
2. reboot system
Actual Results:
All containers fail to start

Expected Results:
Containers continue to work as with previous versions

Comment 1 Stefano Brivio 2025-12-22 09:02:37 UTC
Iyan, thanks a lot for the report.

(In reply to Iyan from comment #0)

> My host has ipv6 disabled via kernel using `ipv6.disable=1`, and the podman
> networks all have `"ipv6_enabled": false`. However, with this new version of
> passt, it seems like it still tries to setup an IPv6, of course fails to do
> so, and the containers are never started.

Oops, of course. The buggy feature comes from https://bugs.passt.top/show_bug.cgi?id=128.

I think there are two issues, actually:

1. Podman should probably tell pasta to disable IPv6, if it's disabled in the kernel. That can be done with the -4 / --ipv4-only option (which is another workaround, by the way: podman run --net=pasta:-4 ...)

2. pasta should... do something different if the kernel runs without IPv6 support or with IPv6 disabled. I'm not quite sure if we should try to enable IPv6 (unless -4 is given) and just ignore ENOTSUPP errors or similar, which looks like the robust and simple solution to me, or if we should check kernel parameters in advance. Any suggestion?

I'll take care of 2. in any case. I'm not entirely sure about 1.

Comment 2 Stefano Brivio 2025-12-22 22:29:56 UTC
Sorry, I meant:

(In reply to Stefano Brivio from comment #1)
> 1. Podman should probably tell pasta to disable IPv6, if it's disabled in
> the kernel.

...if it's disabled in Podman networks with "ipv6_enabled": false.

Comment 4 Fedora Update System 2025-12-24 09:33:43 UTC
FEDORA-2025-4ef71b2b4c (passt-0^20251223.g2ba9fd5-1.fc42) has been submitted as an update to Fedora 42.
https://bodhi.fedoraproject.org/updates/FEDORA-2025-4ef71b2b4c

Comment 5 Fedora Update System 2025-12-24 09:34:23 UTC
FEDORA-2025-02b4d4c380 (passt-0^20251223.g2ba9fd5-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2025-02b4d4c380

Comment 6 Fedora Update System 2025-12-25 01:26:42 UTC
FEDORA-2025-02b4d4c380 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2025-02b4d4c380`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2025-02b4d4c380

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 7 Fedora Update System 2025-12-25 01:48:55 UTC
FEDORA-2025-4ef71b2b4c has been pushed to the Fedora 42 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2025-4ef71b2b4c`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2025-4ef71b2b4c

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 8 Fedora Update System 2025-12-31 00:50:50 UTC
FEDORA-2025-02b4d4c380 (passt-0^20251223.g2ba9fd5-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 9 Fedora Update System 2025-12-31 01:09:51 UTC
FEDORA-2025-4ef71b2b4c (passt-0^20251223.g2ba9fd5-1.fc42) has been pushed to the Fedora 42 stable repository.
If problem still persists, please make note of it in this bug report.


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