20260130 resolve crash in evict_to_len by Firstyear · Pull Request #150 · kanidm/concread

Firstyear · 2026-01-30T08:21:56Z

After a whole day of testing, debugging, logging, I have found the problem @droideck - the haunted lists were being incorrectly cleared which then left dangling pointers in the cache.

This resolves the issue, does a bit of linked list tidy up, adds a ton of assertions, and resolves the issue.

Hope that helps!

#Fixes #149

src/arcache/ll.rs

src/lib.rs

src/internals/hashtrie/cursor.rs

src/arcache/mod.rs

src/internals/hashtrie/cursor.rs

src/arcache/mod.rs

src/internals/hashtrie/cursor.rs

yaleman

I like things that fix other things 🥳

Firstyear · 2026-02-04T00:54:31Z

@yaleman Feedback applied.

@droideck Can you re-run a test to confirm if this resolves the problem? I was able to reproduce and my testing shows it's resolved under high concurrent thread pressure.

droideck · 2026-02-04T01:12:14Z

@yaleman Feedback applied.

Is it pushed? I can't see it...

@droideck Can you re-run a test to confirm if this resolves the problem? I was able to reproduce and my testing shows it's resolved under high concurrent thread pressure.

For some reason, I can't reproduce it on my current VMs with or without the changes (but I'll try more).

Good news that @vashirov was able to hit it before! I provided the prepped build for the env, so hopefully soon we'll share how it went.

And thanks for such a fast investigation/fix response! I really appreciate it!

Firstyear · 2026-02-04T01:59:05Z

@yaleman Feedback applied.

Is it pushed? I can't see it...

My mistake! Pushed now.

Good news that @vashirov was able to hit it before! I provided the prepped build for the env, so hopefully soon we'll share how it went.

And thanks for such a fast investigation/fix response! I really appreciate it!

Sounds good, let me know how it goes :)

Firstyear · 2026-02-06T01:59:04Z

Good news that @vashirov was able to hit it before! I provided the prepped build for the env, so hopefully soon we'll share how it went.

Sorry to be a pain @droideck did you manage to reproduce? Given that this affects not only 389-ds but a few other things we want to do a release soon.

vashirov · 2026-02-06T12:51:54Z

Hey @Firstyear, I ran my reproducer for hours and it didn't crash with this fix. Thanks! :)

droideck

My testing was also not able to hit any panics. Ack from me too!

src/arcache/mod.rs

Firstyear added 2 commits January 30, 2026 13:28

Improvements

75d3d97

Resolve haunted list being evicted prematurely

b3cbdc7

Firstyear requested a review from droideck January 30, 2026 08:21

Firstyear changed the title ~~20260130 diagnostics~~ 20260130 resolve crash in evict_to_len Feb 2, 2026