# CVE-2026-31481: linux: In the Linux kernel, the following vulnerability has been resolved:  tracing: Drain deferred trigger frees if kthread...

CVE-2026-31481 is fixed in linux on 1 platform by DEBIAN-CVE-2026-31481 (version 6.19.11-1), released May 15, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-31481
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0011
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 22, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  tracing: Drain deferred trigger frees if kthread creation fails  Boot-time trigger registration can fail before the trigger-data cleanup kthread exists. Deferring those frees until late init is fine, but the post-boot fallback must still drain the deferred list if kthread creation never succeeds.  Otherwise, boot-deferred nodes can accumulate on trigger_data_free_list, later frees fall back to synchronously freeing only the current object, and the older queued entries are leaked forever.  To trigger this, add the following to the kernel command line:    trace_event=sched_switch trace_trigger=sched_switch.traceon,sched_switch.traceon  The second traceon trigger will fail and be freed. This triggers a NULL pointer dereference and crashes the kernel.  Keep the deferred boot-time behavior, but when kthread creation fails, drain the whole queued list synchronously. Do the same in the late-init drain path so queued entries are not stranded there either.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 6.19.11-1 | [DEBIAN-CVE-2026-31481](https://patchblox.com/security/data/fix/linux/debian-cve-2026-31481.md) | May 15, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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