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

[Roberto Sassu <roberto.sassu@huawei.com>]

> 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.
> 
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