Red Hat Bugzilla – Bug 1261023
login via ssh as remote user often fails with: "Write failed: Broken pipe"
Last modified: 2015-10-05 03:33:48 EDT
Description of problem:
Login attempts via ssh as remote user (AD or IPA) often fails with:
# ssh <user>@<domain>@localhost
Write failed: Broken pipe
The problem was observed on the latest RHEL-7.2 test composes; not sure the issue is caused directly by sssd, but I'm clueless (sssd debugs will be attached). The problems were newer seen on RHEL-7.1 machines. The issue appears only time to time, usually after sssd restart. When join to AD is via winbind the problem does not appear.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. join to AD with realmd
2. try to login via ssh
3. if login succeed try to restart sssd and/or join again
ssh often fails
ssh is reliable
Both authentication and access control part look good in the SSSD logs. Can you add pam and nss responder logs and sshd logs with a high debug level as welll?
It would be also good to attach /var/log/secure
Created attachment 1072168 [details]
strace of sshd child
Thank you for providing the test environment, it was very useful. I used strace to see what sshd is doing and found a "corrupted double-linked list" error in one of the sshd child processes.
Currently I cannot make sense of the output so I attached the file for others to check.
(In reply to Sumit Bose from comment #9)
> Created attachment 1072168 [details]
> strace of sshd child
> Thank you for providing the test environment, it was very useful. I used
> strace to see what sshd is doing and found a "corrupted double-linked list"
> error in one of the sshd child processes.
> Currently I cannot make sense of the output so I attached the file for
> others to check.
Thanks a lot for looking into this.
Do you think it's time to reassign this bugzilla to sshd, then?
We have tracked this down to a security bug, bug 1262914 in glibc.
We have confirmed that this issue is indeed caused by glibc bug 1262914, based on further analysis of the issue. After installing a glibc scratch build with the upstream fix applied, the original sssd issue is no longer reproducible.
I'm closing this as a duplicate of the (internal) glibc 7.2 bug for this issue.
*** This bug has been marked as a duplicate of bug 1263134 ***