CVE-2026-31481: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux Kernel: from 6.19.1, before 6.19.11 (fixed in 6.19.11); version 6.19 only; version 7.0 only

Published 2026-04-22. Last modified 2026-06-17.