Native thread exhaustion (pthread_create failed) with long-running root services (AdGuard) on Android 16 / OxygenOS

[lenox108]

Please answer the following questions for yourself before submitting an issue

• Filters were updated before reproducing an issue
• I checked the knowledge base and found no answer
• I checked to make sure that this issue has not already been filed

AdGuard version

Last

Environment

• OS version:
• Device:

HTTPS filtering

• yes, I do

Root access

• yes, I have it

Integration with AdGuard VPN

• yes, I do

Routing mode

Automatic proxy

Ad Blocking

AdGuard Base filter

Privacy

EasyPrivacy

Social

No response

Annoyances

No response

Security

No response

Language-specific

No response

Other

No response

Which DNS server do you use?

DNS protection disabled

DNS protocol

None

Custom DNS

No response

What Stealth Mode options do you have enabled?

No response

Issue Details

Steps to reproduce:
1.## Problem
On Android 16 (OxygenOS, OnePlus device) KernelSU / KernelSU Next causes
native thread exhaustion for long-running root services.

After some time (usually several hours up to ~1 day), applications that run
as persistent root services fail with the following error:

OutOfMemoryError: pthread_create (4096–4112KB stack) failed

After this happens, the affected app cannot be launched again until it is
fully uninstalled and reinstalled.

This issue is reproducible with AdGuard in root mode, but AdGuard itself
is not the root cause — it is simply a reproducible example of a
long-running root daemon.

---

Environment

• Device: OnePlus
• Android version: Android 16
• ROM: OxygenOS
• Kernel: GKI-based kernel with KernelSU / KernelSU Next
• Root manager: KernelSU Next (also reproducible with Wild KSU)
• Root mode: enabled
• Mount namespace: tested (inherited / private)
• SUSFS / Zygisk Next: tested both enabled and disabled

---

Reproduction steps

1. Enable KernelSU / KernelSU Next
2. Install AdGuard
3. Enable AdGuard root mode (iptables-based filtering, no VPN)
4. Use the device normally (screen on/off, network changes)
5. After several hours or ~1 day, AdGuard crashes
6. Logcat shows:
   OutOfMemoryError: pthread_create failed
7. App cannot be started again until reinstalled

---

Expected behavior

Long-running root services should not exhaust native threads over time.
Thread stacks should be properly released.

---

Actual behavior

Native thread stacks accumulate and eventually prevent new threads
from being created, causing permanent failure of the root service.

---

Similar reports / references

1. AdGuard root mode causes freezes and crashes with KernelSU / KernelSU Next
   Unexpected freeze and then shutdown on OnePlus Nord 4 when using AdGuard root mode with KernelSU #5797
   (Issue does not reproduce when using Magisk instead of KernelSU)

2. AdGuard local proxy / root mode issues with KernelSU
   Local Proxy Mode does not work with KernelSU root #4579

3. KernelSU instability / unexpected reboots on OnePlus devices
   Accidental reboot of Oneplus 13 tiann/KernelSU#2621

---

Additional notes

• The same setup using Magisk root does NOT reproduce this issue
• Disabling root access for the affected app stops the crashes
• This strongly suggests a KernelSU-specific lifecycle or native thread
  cleanup issue rather than an application bug

Expected Behavior

No response

Actual Behavior

adguard_logs_4.12.80_1801_074930.zip

Screenshots

Screenshot 1

Additional Information

No response

[lenox108]

Important update:

I can confirm that this issue does NOT reproduce when using KernelSU in LKM mode.

The same setup (same device, same kernel base, same AdGuard version, same configuration)
works stably in LKM mode without any pthread_create failures.

The problem reproduces only in GKI mode.

This strongly suggests an issue with root lifecycle / native thread cleanup
specific to GKI-based KernelSU integration.

[lenox108]

Important update after extended testing:

I can confirm that this issue is NOT limited to GKI or custom kernels only.

The same AdGuard crash behavior is reproducible even on:

• stock OnePlus kernel
• KernelSU Next in LKM mode (no kernel replacement)

Test conditions were identical:

• same device
• same stock kernel
• same Android / OxygenOS version
• same AdGuard version
• same root / automatic (iptables-based) mode

Results:

• KernelSU Next (GKI): crashes after long uptime
• KernelSU Next (LKM): crashes after long uptime
• Magisk: works stably for extended periods under the same conditions

At this point, stable operation of AdGuard in root / iptables mode
has only been confirmed when using Magisk as the root solution.

This strongly suggests the issue is not only related to missing vendor cleanup
in custom/GKI kernels, but is also related to how KernelSU Next handles
long-running root sessions, su lifecycle, or resource cleanup for processes
that heavily rely on iptables and network hooks.

Magisk appears to handle this use case correctly, while KernelSU Next does not.

[Swen90]

Good day @lenox108
I apologise for the delay. As you've already seen there are multiple cases with the same error OutOfMemoryError: pthread_create failed and only with rooted devices with KernelSU.
But to troubleshoot this issue we need you to collect full Android Bug report. After that, please send that file to qa@adguard.com:
include [android] keyword and 5995 as an issue number in the subject of your email.

This would greatly help to find out the cause of this issue 👍

[lenox108]

Good day @lenox108 I apologise for the delay. As you've already seen there are multiple cases with the same error OutOfMemoryError: pthread_create failed and only with rooted devices with KernelSU. But to troubleshoot this issue we need you to collect full Android Bug report. After that, please send that file to qa@adguard.com: include [android] keyword and 5995 as an issue number in the subject of your email.

This would greatly help to find out the cause of this issue 👍

Good day,

Just to clarify — I have already previously collected and sent the full Android bug reports and all requested logs to qa@adguard.com from the email address lenox30.

Those reports were captured immediately after the crash and include complete system logs, kernel logs, and memory information.

Additionally, I would like to mention that this problem is reproducible on multiple different devices, not just a single phone, and it only occurs when the device is rooted with KernelSU (both GKI and LKM modes).

Under identical conditions, the same setup works stably with Magisk and does not crash.

So at this point the issue appears to be specifically related to KernelSU-based root environments rather than the device or firmware itself.

Please let me know if you need me to capture and send a fresh bug report again — I can reproduce the issue and provide new logs.

Thank you.

[Swen90]

Thank you for the reply!
But I am sorry, but I can not find any email with the 5995 tag or from lenox30 username. So please send us a new bug report as instructed earlier.

[Swen90]

Hello @lenox108
I am currently trying to get java.lang.OutOfMemoryError: pthread_create failed error on our rooted test device with KernelSu Next. Could you please list the steps to reproduce the issue faster?

[lenox108]

Hello @lenox108 I am currently trying to get java.lang.OutOfMemoryError: pthread_create failed error on our rooted test device with KernelSu Next. Could you please list the steps to reproduce the issue faster?

Hello,

Thank you for investigating this issue.

Here are the steps that reproduce the problem reliably on my side:

Device conditions:

• Stock OxygenOS / stock kernel
• Bootloader unlocked
• KernelSU Next installed (both GKI and LKM modes show the same behavior)
• AdGuard for Android installed
• Root permission granted to AdGuard

Steps to reproduce:

1. Enable AdGuard
2. Set AdGuard to "Automatic (root/iptables) mode"
3. Enable HTTPS filtering
4. Keep AdGuard protection running continuously (do not restart the app)
5. Use the device normally:
   • browsing
   • social media apps
   • background network activity
   • downloads/streaming
6. Leave the phone running for several hours

Result:
After some time AdGuard crashes with:
java.lang.OutOfMemoryError: pthread_create failed

Additional observations:

• The issue does NOT happen in AdGuard local VPN mode
• The issue does NOT happen when using Magisk root under the same conditions
• The issue only happens with KernelSU Next (both GKI and LKM)
• The same behavior is reproducible on multiple devices, including OnePlus 13
• On my main device, the crash typically occurs after about 24–36 hours of continuous uptime
• Rebooting temporarily fixes it until resources accumulate again

This suggests the problem appears with long-running root/iptables-based operation specifically under KernelSU environments.

If needed, I can collect and send another fresh bug report immediately after the crash.

[Swen90]

Hi! Thank you for the detailed instruction. I have managed to reproduce the same issue. Currently our team is trying to find a solution. Stay tuned.

[lenox108]

Thank you very much, I hope you solve the problem, I have been trying to solve it for a long time through gpt, I thank him for sending you all the necessary information, because the problem is precisely in root mode and the kernel’s operation with its memory management. пт, 13 февр. 2026 г., 20:00 Swen90 ***@***.***>:

…

*Swen90* left a comment (AdguardTeam/AdguardForAndroid#5995) <#5995 (comment)> Hi! Thank you for the detailed instruction. I have managed to reproduce the same issue. Currently our team is trying to find a solution. Stay tuned. — Reply to this email directly, view it on GitHub <#5995 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/B46ONPAQIVRFU4WXN4SBOKD4LXYIXAVCNFSM6AAAAACSB7A7G2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTQOJXHE3TAMZRHA> . You are receiving this because you were mentioned.Message ID: ***@***.***>