ply_boot_client_process_incoming_replies: Assertion `request_node != NULL' failed

Bug #1810154 reported by Andreas Hasenack
28
This bug affects 3 people
Affects Status Importance Assigned to Milestone
plymouth (Ubuntu)
Fix Released
High
Steve Langasek
Eoan
Fix Released
High
Unassigned

Bug Description

[SRU Justification]
An Ubuntu-specific patch causes a crash in plymouth that does not occur upstream and breaks one of the standard use cases of the plymouth client, to prompt for passwords. While the specific error does not affect password prompting for LUKS due to a different invocation of plymouth, it does break password prompting for ZFS encryption, leaving users at an initramfs prompt on boot.

[Test case]
1. Change to VT3 on your system (so that you are not under a graphical login session) and log in.
2. As root, run: plymouthd --mode=boot --attach-to-session --pid-file=/run/plymouth/pid --tty=/dev/tty8; chvt 8; plymouth --show-splash; plymouth ask-for-password --prompt "This is a password prompt" --command="/bin/cat"; plymouth quit; chvt 3
3. Observe that you are immediately returned to VT3 without being shown a password prompt, and the error message "ply_boot_client_process_incoming_replies: Assertion `request_node != NULL' failed" is printed on the console.
4. Install the plymouth package from eoan-proposed.
5. Repeat step 2.
6. Observe that you are shown a password prompt.
7. Type something into the field and hit enter.
8. Observe that you are returned to VT3 and the text you typed in step 7 has been echoed to the screen, with no error messages.

[Regression potential]
This is an Ubuntu-specific bug due to missing handling of a new upstream message type in an Ubuntu-specific patch. This fixes a crash and has minimal risk of regression.

ubuntu cosmic
plymouth 0.9.3-1ubuntu10
initramfs-tools 0.131ubuntu15

I'm trying to get a password prompt working in the initramfs via plymouth, but I get an assertion error.

This is the sample command I'm running:
plymouth --debug ask-for-password --command=/bin/cat --prompt "Type something"

And this is the output I get:
[./plymouth.c:463] on_password_request:Password request
[ply-event-loop.c:759] ply_event_loop_stop_watching_fd:stopping watching fd 6
[ply-event-loop.c:775] ply_event_loop_stop_watching_fd:removing destination for fd 6
[./plymouth.c:430] on_password_request_execute:executing password request (command /bin/cat)
[ply-event-loop.c:759] ply_event_loop_stop_watching_fd:stopping watching fd 6
[ply-event-loop.c:775] ply_event_loop_stop_watching_fd:removing destination for fd 6
[ply-event-loop.c:759] ply_event_loop_stop_watching_fd:stopping watching fd 6
[ply-event-loop.c:775] ply_event_loop_stop_watching_fd:removing destination for fd 6
plymouth: ./ply-boot-client.c:272: ply_boot_client_process_incoming_replies: Assertion `request_node != NULL' failed.
Aborted

plymouth --ping returns 0. It doesn't matter which --command I try.

Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in plymouth (Ubuntu):
status: New → Confirmed
Revision history for this message
Witold Krecicki (wpk) wrote :

There's a bug in processing cached password replies from plymouthd which causes this assertion, the attached patch fixes this issue (it happens e.g. when using ZFS with native encryption).

Revision history for this message
Ubuntu Foundations Team Bug Bot (crichton) wrote :

The attachment "cached-password-fix.patch" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

tags: added: patch
Changed in plymouth (Ubuntu):
importance: Undecided → Medium
Changed in plymouth (Ubuntu):
importance: Medium → High
Revision history for this message
Witold Krecicki (wpk) wrote :

To clarify, as those questions were asked on IRC:
1. I'm the author of the patch.
2. The bug exists only in Ubuntu, not in upstream version of plymouth - it's caused by the changes included in "misc-changes.patch" (that I'm not touching with at 30 foot pole).

Steve Langasek (vorlon)
description: updated
Changed in plymouth (Ubuntu):
assignee: nobody → Steve Langasek (vorlon)
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package plymouth - 0.9.4git20190712-0ubuntu5

---------------
plymouth (0.9.4git20190712-0ubuntu5) focal; urgency=medium

  * debian/patches/misc-changes.patch: fix an Ubuntu-specific bug in
    handling plymouth ask-for-password with a --command option that results
    in a crash, breaking disk unlocking with zfs. Thank to Witold Krecicki
    for the fix. LP: #1810154.

 -- Steve Langasek <email address hidden> Sat, 14 Dec 2019 10:43:21 -0800

Changed in plymouth (Ubuntu):
status: Confirmed → Fix Released
Revision history for this message
Łukasz Zemczak (sil2100) wrote : Please test proposed package

Hello Andreas, or anyone else affected,

Accepted plymouth into eoan-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/plymouth/0.9.4git20190712-0ubuntu4.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-eoan to verification-done-eoan. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-eoan. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Changed in plymouth (Ubuntu Eoan):
status: New → Fix Committed
tags: added: verification-needed verification-needed-eoan
Revision history for this message
Brian Murray (brian-murray) wrote : [plymouth/eoan] possible regression found

As a part of the Stable Release Updates quality process a search for Launchpad bug reports using the version of plymouth from eoan-proposed was performed and bug 1856712 was found. Please investigate this bug report to ensure that a regression will not be created by this SRU. In the event that this is not a regression remove the "verification-failed-eoan" tag from this bug report and add the tag "bot-stop-nagging" to bug 1856712 (not this bug). Thanks!

tags: added: verification-failed-eoan
Mathew Hodson (mhodson)
Changed in plymouth (Ubuntu Eoan):
importance: Undecided → High
Steve Langasek (vorlon)
tags: removed: verification-failed-eoan
Revision history for this message
Steve Langasek (vorlon) wrote :

I've confirmed that after upgrade to plymouth from unstable, the testcase passes (and zfs initramfs decryption works now in Ubuntu 19.10).

tags: added: verification-done-eoan
removed: verification-needed verification-needed-eoan
Revision history for this message
Chris Halse Rogers (raof) wrote : Update Released

The verification of the Stable Release Update for plymouth has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package plymouth - 0.9.4git20190712-0ubuntu4.1

---------------
plymouth (0.9.4git20190712-0ubuntu4.1) eoan; urgency=medium

  * debian/patches/misc-changes.patch: fix an Ubuntu-specific bug in
    handling plymouth ask-for-password with a --command option that results
    in a crash, breaking disk unlocking with zfs. Thank to Witold Krecicki
    for the fix. LP: #1810154.

 -- Steve Langasek <email address hidden> Sat, 14 Dec 2019 10:43:21 -0800

Changed in plymouth (Ubuntu Eoan):
status: Fix Committed → Fix Released
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