CVE-2026-46196
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel related to tracepoints that occurs during the failure of the func_add() function in tracepoint_add_func(). In the event of an error, the function does not call the corresponding unregfunc(), leading to an incorrect reference state.
Risk Assessment
This vulnerability may lead to uncontrolled reference count growth in the system, resulting in excessive system load and potential memory leaks. In the case of syscall tracepoints, this can lead to inefficient application performance until the system is rebooted.
Recommendation
It is recommended to update the Linux kernel to the latest version that includes fixes for this vulnerability. Additionally, system load should be monitored and regular reviews of tracepoint configurations should be conducted.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func() When a tracepoint goes through the 0 -> 1 transition, tracepoint_add_func() invokes the subsystem's ext->regfunc() before attempting to install the new probe via func_add(). If func_add() then fails (for example, when allocate_probes() cannot allocate a new probe array under memory pressure and returns -ENOMEM), the function returns the error without calling the matching ext->unregfunc(), leaving the side effects of regfunc() behind with no installed probe to justify them. For syscall tracepoints this is particularly unpleasant: syscall_regfunc() bumps sys_tracepoint_refcount and sets SYSCALL_TRACEPOINT on every task. After a leaked failure, the refcount is stuck at a non-zero value with no consumer, and every task continues paying the syscall trace entry/exit overhead until reboot. Other subsystems providing regfunc()/unregfunc() pairs exhibit similarly scoped persistent state. Mirror the existing 1 -> 0 cleanup and call ext->unregfunc() in the func_add() error path, gated on the same condition used there so the unwind is symmetric with the registration.