Bug 2464782 - [Regression] Cannot log in to FreeIPA account with password immediately after boot
Summary: [Regression] Cannot log in to FreeIPA account with password immediately after...
Keywords:
Status: POST
Alias: None
Product: Fedora
Classification: Fedora
Component: sssd
Version: 44
Hardware: Unspecified
OS: Unspecified
unspecified
high
Target Milestone: ---
Assignee: Alexey Tikhonov
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-03 20:18 UTC by James
Modified: 2026-05-11 08:29 UTC (History)
7 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: Bug
Embargoed:


Attachments (Terms of Use)
krb5_child.log (77.79 KB, text/plain)
2026-05-04 09:40 UTC, James
no flags Details

Description James 2026-05-03 20:18:00 UTC
Description of problem:
I cannot log in to my FreeIPA account via GDM or console using sssd. This started following in an upgrade to Fedora 44.

Version-Release number of selected component (if applicable):
sssd-common-2.13.0-1.fc44.x86_64

How reproducible:
Consistently, after reboot.

Steps to Reproduce:
1. Reboot.
2. Attempt to log in with password.

Actual results:
Access denied.

Expected results:
Access granted.

Additional info:
Normal service can be restored by clearing the sss cache, then restarting sssd.

Comment 1 James 2026-05-03 20:18:52 UTC
# journalctl -b -u sssd
May 03 21:09:12 flexo.cb.ettle.org.uk systemd[1]: Starting sssd.service - System Security Services Dae>
May 03 21:09:12 flexo.cb.ettle.org.uk sssd[1783]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_be[1869]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_autofs[1970]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_sudo[1968]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_ssh[1967]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_pam[1966]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_pac[1971]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_nss[1965]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk systemd[1]: Started sssd.service - System Security Services Daem>
May 03 21:09:30 flexo.cb.ettle.org.uk krb5_child[4526]: Permission denied
May 03 21:09:12 flexo.cb.ettle.org.uk systemd[1]: Starting sssd.service - System Security Services Dae>
May 03 21:09:12 flexo.cb.ettle.org.uk sssd[1783]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_be[1869]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_autofs[1970]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_sudo[1968]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_ssh[1967]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_pam[1966]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_pac[1971]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk sssd_nss[1965]: Starting up
May 03 21:09:12 flexo.cb.ettle.org.uk systemd[1]: Started sssd.service - System Security Services Daem>
May 03 21:09:30 flexo.cb.ettle.org.uk krb5_child[4526]: Permission denied
May 03 21:09:36 flexo.cb.ettle.org.uk krb5_child[4909]: Permission denied
May 03 21:09:46 flexo.cb.ettle.org.uk krb5_child[4920]: Permission denied
May 03 21:09:56 flexo.cb.ettle.org.uk krb5_child[5158]: Permission denied

Here's where I restarted sssd:

May 03 21:10:26 flexo.cb.ettle.org.uk systemd[1]: Stopping sssd.service - System Security Services Dae>
May 03 21:10:26 flexo.cb.ettle.org.uk sssd_pam[1966]: Shutting down (status = 0)
May 03 21:10:26 flexo.cb.ettle.org.uk sssd_ssh[1967]: Shutting down (status = 0)
May 03 21:10:26 flexo.cb.ettle.org.uk sssd_pac[1971]: Shutting down (status = 0)
May 03 21:10:26 flexo.cb.ettle.org.uk sssd_sudo[1968]: Shutting down (status = 0)
May 03 21:10:26 flexo.cb.ettle.org.uk sssd_autofs[1970]: Shutting down (status = 0)
May 03 21:10:26 flexo.cb.ettle.org.uk sssd_be[1869]: Shutting down (status = 0)
May 03 21:10:26 flexo.cb.ettle.org.uk sssd_nss[1965]: Shutting down (status = 0)
May 03 21:10:26 flexo.cb.ettle.org.uk systemd[1]: sssd.service: Deactivated successfully.
May 03 21:10:26 flexo.cb.ettle.org.uk systemd[1]: Stopped sssd.service - System Security Services Daem>
May 03 21:10:26 flexo.cb.ettle.org.uk systemd[1]: sssd.service: Consumed 1.192s CPU time over 1min 14.>
May 03 21:10:38 flexo.cb.ettle.org.uk systemd[1]: Starting sssd.service - System Security Services Dae>
May 03 21:10:38 flexo.cb.ettle.org.uk sssd[5484]: Starting up
May 03 21:10:38 flexo.cb.ettle.org.uk sssd_be[5485]: Starting up
May 03 21:10:38 flexo.cb.ettle.org.uk sssd_pac[5492]: Starting up
May 03 21:10:38 flexo.cb.ettle.org.uk sssd_pam[5488]: Starting up
May 03 21:10:38 flexo.cb.ettle.org.uk sssd_ssh[5489]: Starting up
May 03 21:10:38 flexo.cb.ettle.org.uk sssd_autofs[5491]: Starting up

Comment 2 Alexey Tikhonov 2026-05-04 06:39:01 UTC
(In reply to James from comment #1)
> May 03 21:09:30 flexo.cb.ettle.org.uk krb5_child[4526]: Permission denied

Could you please attach `/var/log/sssd/krb5_child.log`?

Comment 3 James 2026-05-04 09:40:49 UTC
Created attachment 2139368 [details]
krb5_child.log

Comment 4 Alexey Tikhonov 2026-05-04 10:17:17 UTC
(In reply to James from comment #0)
> This started following in an upgrade to Fedora 44.

What version did you upgrade from?

> [krb5_child[4496]] [validate_tgt] (0x0020): [RID#646] error reading keytab [/etc/krb5.keytab], not verifying TGT.
> [krb5_child[4496]] [debug_and_log] (0x0020): [RID#646] 2587: [13][Permission denied]

This is likely due to a bug in the logic that drops `cap_dac_read_search` soon after process started, but:
 - IIUC, it should have been seen with sssd-2.12 as well
 - maybe it's not the reason of an actual fail:
```
[krb5_child[4683]] [sss_krb5_auth_methods_answer] (0x4000): [RID#633] Got question [password].
[krb5_child[4683]] [debug_and_log] (0x0020): [RID#633] 2540: [-1765328360][Preauthentication failed]
```

Could you please make a quick check if bug is still observed with `krb5_validate = false` in the domain section of 'sssd.conf'?

Comment 5 Alexey Tikhonov 2026-05-04 10:47:05 UTC
(In reply to Alexey Tikhonov from comment #4)
> 
> > [krb5_child[4496]] [validate_tgt] (0x0020): [RID#646] error reading keytab [/etc/krb5.keytab], not verifying TGT.
> > [krb5_child[4496]] [debug_and_log] (0x0020): [RID#646] 2587: [13][Permission denied]
> 
> This is likely due to a bug in the logic that drops `cap_dac_read_search`
> soon after process started

```
   *  (2026-04-30 23:06:48): [krb5_child[4517]] [unpack_buffer] (0x0100): [RID#632] cmd [249 (pre-auth)] uid [1367600004] gid [1367600004] validate [true] enterprise principal [false] offline [true] UPN [james.ORG.UK]
   *  (2026-04-30 23:07:02): [krb5_child[4517]] [unpack_buffer] (0x0100): [RID#632] cmd [241 (auth)] uid [1367600004] gid [1367600004] validate [true] enterprise principal [false] offline [false] UPN [james.ORG.UK]
```

Since `krb5_child[4517]` is started with `offline [true]`, `copy_keytab_into_memory()` isn't executed:
https://github.com/SSSD/sssd/blob/e5b65979f11e10ffafa398fe38e4d1cf63cd99bf/src/providers/krb5/krb5_child.c#L4224

But 'auth' in the same session is called with `offline [false]` (and `validate [true]`)  --  TGT validation fails because keytab isn't available.

Perhaps it is a race condition: auth attempt is started before SSSD goes online and completes when it is already discovered & connected to IPA server...

If that's the case, then cache removal is a red herring  --  simply delaying an auth attempt after reboot should hide an issue as well.

Comment 6 James 2026-05-04 15:03:05 UTC
(In reply to Alexey Tikhonov from comment #4)
> (In reply to James from comment #0)
> > This started following in an upgrade to Fedora 44.
> 
> What version did you upgrade from?
> 
> > [krb5_child[4496]] [validate_tgt] (0x0020): [RID#646] error reading keytab [/etc/krb5.keytab], not verifying TGT.
> > [krb5_child[4496]] [debug_and_log] (0x0020): [RID#646] 2587: [13][Permission denied]
> 
> This is likely due to a bug in the logic that drops `cap_dac_read_search`
> soon after process started, but:
>  - IIUC, it should have been seen with sssd-2.12 as well
>  - maybe it's not the reason of an actual fail:
> ```
> [krb5_child[4683]] [sss_krb5_auth_methods_answer] (0x4000): [RID#633] Got
> question [password].
> [krb5_child[4683]] [debug_and_log] (0x0020): [RID#633] 2540:
> [-1765328360][Preauthentication failed]
> ```
> 
> Could you please make a quick check if bug is still observed with
> `krb5_validate = false` in the domain section of 'sssd.conf'?

The most recent upgrade history was: sssd-krb5-0:2.12.0-1.fc43.x86_64 -> sssd-krb5-0:2.12.0-4.fc44.x86_64 (f43 -> 44 upgrade), then most recently to sssd-krb5-common-0:2.13.0-1.fc44.x86_64 -- however I don't know which particular step was the cause. I'll try downgrading to 2.12 and see if that makes it work again.

The bug goes away with krb5_valid = false.

Comment 7 James 2026-05-04 15:14:56 UTC
Things are OK with sssd-krb5-0:2.12.0-4.fc44.x86_64.

Comment 8 Alexey Tikhonov 2026-05-04 15:48:51 UTC
(In reply to James from comment #7)
> Things are OK with sssd-krb5-0:2.12.0-4.fc44.x86_64.

Hm... this doesn't match my understanding of a bug and this bothers me...

Thanks for help so far.

Could you may be conduct two other test (with default `krb5_validate = true`):

(1) let SSSD to go online after reboot (perhaps just waiting few minutes after reboot should be enough) and check the auth

(2) check if copr build https://dashboard.packit.dev/jobs/copr/3537954 resolves an issue
This is a build of fix candidate - https://github.com/SSSD/sssd/pull/8671

Comment 9 James 2026-05-04 19:26:58 UTC
I think you're right about the cache purge being a red herring, I was able to get it working by just restarting sssd (on a fresh F44 install).

(1) Waiting a few minutes also works.

(2) Looks like this has fixed it (tested across 3 reboots).

Comment 10 Alexey Tikhonov 2026-05-06 11:12:15 UTC
Upstream PR: https://github.com/SSSD/sssd/pull/8671

Comment 11 Alexey Tikhonov 2026-05-11 06:40:40 UTC
Fixed upstream as of https://github.com/SSSD/sssd/commit/b070171e8371ce9be20c0554617b35d13a2ef17c

Comment 12 Alexey Tikhonov 2026-05-11 06:43:31 UTC
sssd-2-13 backport: https://github.com/SSSD/sssd/pull/8687

Comment 13 Alexey Tikhonov 2026-05-11 08:29:27 UTC
(In reply to Alexey Tikhonov from comment #12)
> sssd-2-13 backport: https://github.com/SSSD/sssd/pull/8687

https://github.com/SSSD/sssd/commit/6e2b87aa43e15f18c10d859bbed59dab314ffed1


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