[syzbot] Monthly lsm report (Apr 2026)

[syzbot] Monthly lsm report (Apr 2026)

[syzbot]

Hello lsm maintainers/developers,

This is a 31-day syzbot report for the lsm subsystem.
All related reports/information can be found at:
https://syzkaller.appspot.com/upstream/s/lsm

During the period, 0 new issues were detected and 0 were fixed.
In total, 3 issues are still open and 45 have already been fixed.

Some of the still happening issues:

Ref Crashes Repro Title
<1> 95      Yes   INFO: task hung in process_measurement (3)
                  https://syzkaller.appspot.com/bug?extid=cb9e66807bcb882cd0c5
<2> 68      Yes   possible deadlock in keyring_clear (3)
                  https://syzkaller.appspot.com/bug?extid=f55b043dacf43776b50c
<3> 31      Yes   INFO: task hung in ima_file_free (4)
                  https://syzkaller.appspot.com/bug?extid=8036326eebe7d0140944

---
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Re: [syzbot] Monthly lsm report (Apr 2026)

[Paul Moore]

On Tue, Apr 14, 2026 at 2:48 AM syzbot
<syzbot+liste5004e02dae137bbd339@syzkaller.appspotmail.com> wrote:
>
> Hello lsm maintainers/developers,
>
> This is a 31-day syzbot report for the lsm subsystem.
> All related reports/information can be found at:
> https://syzkaller.appspot.com/upstream/s/lsm
>
> During the period, 0 new issues were detected and 0 were fixed.
> In total, 3 issues are still open and 45 have already been fixed.
>
> Some of the still happening issues:
>
> Ref Crashes Repro Title
> <1> 95      Yes   INFO: task hung in process_measurement (3)
>                   https://syzkaller.appspot.com/bug?extid=cb9e66807bcb882cd0c5
> <2> 68      Yes   possible deadlock in keyring_clear (3)
>                   https://syzkaller.appspot.com/bug?extid=f55b043dacf43776b50c
> <3> 31      Yes   INFO: task hung in ima_file_free (4)
>                   https://syzkaller.appspot.com/bug?extid=8036326eebe7d0140944

Mimi, Roberto,

If I recall correctly, we've discussed the process measurement issue
before, and I thought it was being resolved.  What is the current
status on a fix?

I don't recall discussing the ima_file_free() issue, but it looks like
the syzbot reports go back to 2024; is there a fix under development
for that?

Thanks.

> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> To disable reminders for individual bugs, reply with the following command:
> #syz set <Ref> no-reminders
>
> To change bug's subsystems, reply with:
> #syz set <Ref> subsystems: new-subsystem
>
> You may send multiple commands in a single email message.

-- 
paul-moore.com

Re: [syzbot] Monthly lsm report (Apr 2026)

[Paul Moore]

On Tue, Apr 14, 2026 at 2:48 AM syzbot
<syzbot+liste5004e02dae137bbd339@syzkaller.appspotmail.com> wrote:
>
> Hello lsm maintainers/developers,
>
> This is a 31-day syzbot report for the lsm subsystem.
> All related reports/information can be found at:
> https://syzkaller.appspot.com/upstream/s/lsm
>
> During the period, 0 new issues were detected and 0 were fixed.
> In total, 3 issues are still open and 45 have already been fixed.
>
> Some of the still happening issues:
>
> Ref Crashes Repro Title
> <1> 95      Yes   INFO: task hung in process_measurement (3)
>                   https://syzkaller.appspot.com/bug?extid=cb9e66807bcb882cd0c5
> <2> 68      Yes   possible deadlock in keyring_clear (3)
>                   https://syzkaller.appspot.com/bug?extid=f55b043dacf43776b50c

Jarkko, David,

Do we have a fix for the keyring_clear() issue, or is it not a real problem?

> <3> 31      Yes   INFO: task hung in ima_file_free (4)
>                   https://syzkaller.appspot.com/bug?extid=8036326eebe7d0140944
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> To disable reminders for individual bugs, reply with the following command:
> #syz set <Ref> no-reminders
>
> To change bug's subsystems, reply with:
> #syz set <Ref> subsystems: new-subsystem
>
> You may send multiple commands in a single email message.

-- 
paul-moore.com

RE: [syzbot] Monthly lsm report (Apr 2026)

[Roberto Sassu]

> From: Paul Moore <paul@paul-moore.com>
> Sent: Tuesday, April 14, 2026 3:59 PM
> On Tue, Apr 14, 2026 at 2:48 AM syzbot
> <syzbot+liste5004e02dae137bbd339@syzkaller.appspotmail.com> wrote:
> >
> > Hello lsm maintainers/developers,
> >
> > This is a 31-day syzbot report for the lsm subsystem.
> > All related reports/information can be found at:
> > https://syzkaller.appspot.com/upstream/s/lsm
> >
> > During the period, 0 new issues were detected and 0 were fixed.
> > In total, 3 issues are still open and 45 have already been fixed.
> >
> > Some of the still happening issues:
> >
> > Ref Crashes Repro Title
> > <1> 95      Yes   INFO: task hung in process_measurement (3)
> >
> https://syzkaller.appspot.com/bug?extid=cb9e66807bcb882cd0c5
> > <2> 68      Yes   possible deadlock in keyring_clear (3)
> >
> https://syzkaller.appspot.com/bug?extid=f55b043dacf43776b50c
> > <3> 31      Yes   INFO: task hung in ima_file_free (4)
> >
> > https://syzkaller.appspot.com/bug?extid=8036326eebe7d0140944
> 
> Mimi, Roberto,
> 
> If I recall correctly, we've discussed the process measurement issue before,
> and I thought it was being resolved.  What is the current status on a fix?
> 
> I don't recall discussing the ima_file_free() issue, but it looks like the syzbot
> reports go back to 2024; is there a fix under development for that?

I looked at some of the reports. My impression (can be wrong) is that the
syzbot report involves us also when a filesystem gets stuck.

For example, if you see:

https://syzkaller.appspot.com/text?tag=CrashReport&x=160ddb02580000

PID 6887 cannot progress because iint->mutex is likely held by PID 6895.
The last function I see in PID 6895 is io_schedule() which suggests me
that there is an I/O wait that could not be satisfied. PID 6888 cannot progress
as well because is waiting for jfs_get_block(), but PID 6895 is past that
(possibly holding the needed lock).

Sure, it is possible that there is a lock inversion that I missed, but I didn't
find it yet.

Roberto

> Thanks.
> 
> > ---
> > This report is generated by a bot. It may contain errors.
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@googlegroups.com.
> >
> > To disable reminders for individual bugs, reply with the following
> command:
> > #syz set <Ref> no-reminders
> >
> > To change bug's subsystems, reply with:
> > #syz set <Ref> subsystems: new-subsystem
> >
> > You may send multiple commands in a single email message.
> 
> --
> paul-moore.com

Re: [syzbot] Monthly lsm report (Apr 2026)

[Jarkko Sakkinen]

On Tue, Apr 14, 2026 at 10:02:13AM -0400, Paul Moore wrote:
> On Tue, Apr 14, 2026 at 2:48 AM syzbot
> <syzbot+liste5004e02dae137bbd339@syzkaller.appspotmail.com> wrote:
> >
> > Hello lsm maintainers/developers,
> >
> > This is a 31-day syzbot report for the lsm subsystem.
> > All related reports/information can be found at:
> > https://syzkaller.appspot.com/upstream/s/lsm
> >
> > During the period, 0 new issues were detected and 0 were fixed.
> > In total, 3 issues are still open and 45 have already been fixed.
> >
> > Some of the still happening issues:
> >
> > Ref Crashes Repro Title
> > <1> 95      Yes   INFO: task hung in process_measurement (3)
> >                   https://syzkaller.appspot.com/bug?extid=cb9e66807bcb882cd0c5
> > <2> 68      Yes   possible deadlock in keyring_clear (3)
> >                   https://syzkaller.appspot.com/bug?extid=f55b043dacf43776b50c
> 
> Jarkko, David,
> 
> Do we have a fix for the keyring_clear() issue, or is it not a real problem?

I'll take analyzing this to my todo list for next week (post first PR).

BR, Jarkko

Re: [syzbot] Monthly lsm report (Apr 2026)

[Jarkko Sakkinen]

On Tue, Apr 14, 2026 at 10:02:13AM -0400, Paul Moore wrote:
> On Tue, Apr 14, 2026 at 2:48 AM syzbot
> <syzbot+liste5004e02dae137bbd339@syzkaller.appspotmail.com> wrote:
> >
> > Hello lsm maintainers/developers,
> >
> > This is a 31-day syzbot report for the lsm subsystem.
> > All related reports/information can be found at:
> > https://syzkaller.appspot.com/upstream/s/lsm
> >
> > During the period, 0 new issues were detected and 0 were fixed.
> > In total, 3 issues are still open and 45 have already been fixed.
> >
> > Some of the still happening issues:
> >
> > Ref Crashes Repro Title
> > <1> 95      Yes   INFO: task hung in process_measurement (3)
> >                   https://syzkaller.appspot.com/bug?extid=cb9e66807bcb882cd0c5
> > <2> 68      Yes   possible deadlock in keyring_clear (3)
> >                   https://syzkaller.appspot.com/bug?extid=f55b043dacf43776b50c
> 
> Jarkko, David,
> 
> Do we have a fix for the keyring_clear() issue, or is it not a real problem?

I'm actually doing something to this already: trying to write a
simplified reproducer. But yeah most likely still will take up until
some point next week.

BR, Jarkko