CVE-2026-68090

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

debugobjects: Plug race against a concurrent OOM disable

syzbot reported a puzzling splat:

WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20

stub_timer() is installed as timer callback function in

hrtimer_fixup_assert_init(), which is invoked when

debug_object_assert_init() can't find a shadow object. In that case debug

objects emits a warning about it before invoking the fixup.

Though the provided console log lacks this warning and instead has the

following a few seconds before the splat:

ODEBUG: Out of memory. ODEBUG disabled

So the object was looked up in debug_object_assert_init() and the lookup

failed due a concurrent out of memory situation which disabled debug

objects and freed the shadow objects:

debug_object_assert_init()

if (!debug_objects_enabled)

return; obj = alloc();

if (!obj) {

// Out of memory

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References