> Source: [sk184340](https://support.checkpoint.com/results/sk/sk184340)

# sk184340 - Security Gateway working in SecureXL User Mode (UPPAK) crashes because of SND core flapping and USIM_x86 segmentation faults

| Property | Value |
|----------|-------|
| Solution ID | sk184340 |
| Date Created | 2025-11-30 |
| Last Modified | 2026-03-09 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R82, R81.20 |
| OS | Gaia |
| Platform | 9000 |

## Symptoms

- * When working in SecureXL User Mode (UPPAK), Security Gateway crashes with kernel logs showing segmentation faults in the USIM_x86 process.
* The *$FWDIR/log/dsd.elg* logs show SND core flapping in dynamic balancing concurrent with the segmentation faults:  
  `
  update_interfaces_uppak: added 2 SNDs for UPPAK`  
  `
  update_interfaces_uppak: removed 2 SNDs for UPPAK`  
  `
  recover_record_runtime_state: Recording runtime state`  
  `
  FWs filtered average: 60.3 | SNDs filtered average: 0.0`  
  `
  `  
  `
  `
* The */var/log/usim_x86.elg* log shows:  
  `
  [UPPAK];host_if_msg_ds_update: sent sleep trigger to SND thread on cpu 4, rc = 1`  
  `
  [SIM4];packet_thread: cpu 5 qid 4 going to sleep ...`  
  `
  [UPPAK];host_if_msg_ds_update: sent sleep trigger to SND thread on cpu 5, rc = 1`  
  `
  [SIM4];EAL: Core MIA. Last seen 11999ms ago.`  
  `
  [UPPAK];Worker on CPU 4 is inactive, excusing it from wd trigger`  
  `
  [SIM4];EAL: Core died. Last seen 23999ms ago.`  
  `
  [UPPAK];Threads got STUCK `

## Cause

SND (Secure Network Distributor) core flapping causes segmentation faults in the USIM_x86 process.

## Solution

This problem was fixed. The fix is included in:

* [Jumbo Hotfix Accumulator for R82](https://sc1.checkpoint.com/documents/Jumbo_HFA/R82/Default.htm) starting from Take 60
* [Jumbo Hotfix Accumulator for R81.20](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.20/Default.htm) starting from Take 120

If you choose not to upgrade, Check Point can supply a **Hotfix** . [Contact Check Point Support](https://www.checkpoint.com/support-services/contact-support/) to get a Hotfix for this issue.  
A Support Engineer will make sure the Hotfix is compatible with your environment before providing the Hotfix.  
For faster resolution and verification, please collect [CPinfo files](http://supportcontent.checkpoint.com/solutions?id=sk92739) from the Security Management Server and Security Gateways involved in the case.

**Hotfix installation instructions:**   
Refer to [sk168597 - How to install a Hotfix](https://support.checkpoint.com/results/sk/sk168597).

<br />

---

# Agent Instructions

This content is from the Check Point Support Center (https://support.checkpoint.com), the official knowledge base for Check Point cybersecurity products.

## Navigating This Knowledge Base

- **Complete index**: [llms.txt](https://support.checkpoint.com/llms.txt)
- **All SK articles**: [SecureKnowledge Sitemap](https://support.checkpoint.com/sitemaps/secureknowledge-sitemap-index.xml)
- **SK article URL pattern**: `https://support.checkpoint.com/results/sk/{skId}`
- **Markdown responses**: AI bot User-Agents automatically receive `text/markdown` content