Signal-desktop: Deleted user from the group still receives messages

[duub]

• [X] I have searched open and closed issues for duplicates
  

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Bug description

A member of a group were deleted, but still appears in the list of group members on the desktop app, not in the mobile app and is receiving my messages, not the ones from the people using the mobile app.

Steps to reproduce

1. Have the both apps synced
2. delete the member
3. delete the mobile app, reinstall, resync with desktop
4. I had to be readed in the group or at least in the mobile app i hadn't the group
5. send a message to the group using the desktop app

Actual result:

the list of the members in the desktop app has a deleted member and him still receives my messages.

Expected result:

the list of the members in the desktop app be synced with the mobile one.

Screenshots

not know what to screenshoot... the list of the users difering from desktop and mobile?

Platform info

Signal version: Desktop: 1.6.1 Mobile: 4.18.0

Operating System: Windows 10 64-bit

Linked device version: Android 8.1.0

Link to debug log

[gasi-signal]

@duub Thanks for the bug report. Could you please provide debug logs from both Signal Desktop and Signal Android around the time this happens? That will help us diagnose the issue.

[MBLHarrison]

@duub When you say deleted? Are you saying you are deleting another user out of the group? Or is the user removing themselves

[Trolldemorted]

@gasi-signal what happens if the group leave message on android fails to send?

[duub]

@gasi-signal sorry I noticed this issue some time after that event happened, there's no log data old enough.

@MBLHarrison Someone of the group deleted the user several time ago. But in the desktop app didn't sync this event.

[sexybiggetje]

I have this issue as well. The process:

I was in a group, this group had people that weren't in my contact list.
I decided to leave the group. I removed myself on mobile.
Then on the desktop app, I still kept receiving messages, but only from the one person that was actually in my contacts.

This person then re added me to the group, since this was annoying so we could try to remove me again. At this point I was in the group on the desktop, receiving messages from everybody. However the group didn't show up on mobile. I'm unable to remove myself from the group now at all because the desktop doesn't provide this option.

This is my desktop debug log, it has been running all day if that helps gather data; https://debuglogs.org/da355bc82585d8af0922565fc453c5d95854354542cd2bb28953edb79f3a57a2

I'm unable to properly capture the mobile log at this point.

I hope my detailed description above helps? Maybe it's related to the to me unknown contacts?

[andy5995]

@sexybiggetje I have a friend this happened to. He was in a group I was in, which had about 5 people in it. After he left the group, he still received messages I sent to the group (but not from anyone else who was in the group).

[scottnonnenberg-signal]

No, it likely has to do with reliable connectivity at the time of the add/remove from the group.

Because the Signal server doesn't know anything about groups, group membership is maintained by all group members. So if one client doesn't receive the message that a given member was added, it continues merrily along with an incorrect member list. Generally, the solution is to be re-added, and then ensure that all devices receive your second attempt at removing yourself from the group. But it sounds like that second add also failed! One way that can happen is if your internet connection is a little questionable.

It can also happen if people in the group have old desktop instances which haven't been online in a long time. They can miss the group update because only 1000 messages are saved for them when they come back.

[gregoriomezquita]

Same happen in an android group created by me. One of the member deleted himself but his desktop app in Windows 10 still receives messages from the group. Membership sync doesn't work in desktop app. This is an unacceptable leak because the rest of the members don't want to share messages with the deleted member. Also there seems to be no way to solve this situation in desktop app.

[scottnonnenberg-signal]

@gregoriomezquita The problem isn't necessarily just his desktop, but the devices in the group which still believe that that member is in the group. You can fix this by updating the group from a mobile device which believes that he is not in the group - that will result in an update which should update the group membership on the other devices still sending to him.

[gregoriomezquita]

Thanks for the response.
What do you mean by updating the group?. I'm running the app in Android and
always update the app to the latest version. However I can't see any way to
"update the group" as you mentioned. Please, can you be more explicit in
how to do that in the Android app ? In my mobile device
the deleted member doesn't appear as member of the group so I could fix
the problem.
Thanks in advance

El lun., 13 may. 2019 a las 18:37, Scott Nonnenberg (<
[email protected]>) escribió:

@gregoriomezquita https://github.com/gregoriomezquita The problem isn't
necessarily just his desktop, but the devices in the group which still
believe that that member is in the group. You can fix this by updating the
group from a mobile device which believes that he is not in the group -
that will result in an update which should update the group membership on
the other devices still sending to him.

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[scottnonnenberg-signal]

@gregoriomezquita "Update the group" means making a change to the group - its name, membership, or icon. That will then result in a group update message going to all members, which should fix things.

[gregoriomezquita]

@scottnonnenberg-signal I updated the group name twice but he is still receiving messages from at least one of the member but not from me which is an advance. I

[ecerum]

Hi there,
I am receiving messages from some of the members of a group I left almost two months ago in the desktop Signal app v1.24.1 I have got installed in two differentes computers running Windows 10.
I don't receive the messages on the mobile app v4.39.4 running Android 8.1.0.

From my point of view this is an unacceptable and critical error, for privacy, comms integrity... etc. that should be addressed as soon as possible.
The workaround/answer provided stating that some, any or all of the group members should do something sounds a bit strange, since the case must be considered and handled by the service itself with no member intervention.
Hope it is solved soon.
Regards