The Linux kernel debugobjects subsystem had a race condition triggered by a concurrent out-of-memory (OOM) event that disables debug objects and frees shadow objects. During this state, debug_object_assert_init() and debug_object_activate() may invoke a timer callback unconditionally despite debug objects being disabled, leading to dysfunctional timer behavior. The vulnerability was reported by syzbot and involves the stub_timer callback in hrtimer_fixup_assert_init(). The patch plugs this hole by adding checks to ensure debug objects are enabled before calling print and fixup functions in these two functions.

The vulnerability causes the timer callback function to become dysfunctional when debug objects are disabled due to an OOM condition. This could lead to kernel warnings or instability related to timer handling in debug object code paths. There is no indication of direct security compromise or exploitation in the wild.

A fix has been implemented in the Linux kernel source to check whether debug objects are still enabled before invoking print and fixup functions in debug_object_assert_init() and debug_object_activate(). Users should update to the fixed kernel version once available. Patch status is not yet confirmed in the provided data — check the official Linux kernel advisories or vendor updates for current remediation guidance.