> Source: [sk183822](https://support.checkpoint.com/results/sk/sk183822)

# sk183822 - Security Gateway stops forwarding traffic during HTTP/2 sessions

| Property | Value |
|----------|-------|
| Solution ID | sk183822 |
| Date Created | 2025-09-03 |
| Last Modified | 2026-05-06 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R82, R81.20 |

## Symptoms

- * */var/log/messages* shows these messages:   

  ```
  
  kernel:[SIM4];cpaq_cbuf_send: cpaq_cbuf_call_api_end_ex failed
  kernel:[SIM4];cpaq_cbuf_send_buffer: send chunk num 0 failed
  kernel:[SIM4];sim_cphwd_stats_cb: failed to create cpaq buffer
  ```

  <br />

* *fwk_softlock.elg* file shows persistent soft lockups with these logs:  

  ```
  
  [instance_]: Received thread_blocker signal
  [instance_]: [1] 0x529dd8d0 [/lib64/libpthread.so.0] (offset 0xf8d0)
  [instance_]: [2] ws_http2_frame_queue_get_amount_of_bytes_by_status.constprop.1102 [/opt/CPsuite-R81.20/fw1/lib/libfw_kern_64_us_optimized_9.so] (offset 0xb87ff0)
  [instance_]: [3] ws_http2_pass [/opt/CPsuite-R81.20/fw1/lib/libfw_kern_64_us_optimized_9.so] (offset 0xa3e085)
  [instance_]: [4] ws_http2_handle_stream_action [/opt/CPsuite-R81.20/fw1/lib/libfw_kern_64_us_optimized_9.so] (offset 0xa43946)
  [instance_]: [5] ws_connection2_read_handler
  ```

  <br />

## Cause

HTTP/2 frame queues can become filled with streams stuck in a hold state. This situation can cause `ws_http2_frame_queue_get_amount_of_bytes_by_status` to consume more resources than intended.

## Solution

This problem was fixed. The fix is included in:

* [Check Point R82.10](https://support.checkpoint.com/results/sk/sk183506)
* [Jumbo Hotfix Accumulator for R82](https://sc1.checkpoint.com/documents/Jumbo_HFA/R82/Default.htm) starting from Take 44
* [Jumbo Hotfix Accumulator for R81.20](https://sc1.checkpoint.com/documents/Jumbo_HFA/R81.20/Default.htm) starting from Take 119

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 />

---

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