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.
References
Configurations
Configuration 1 (hide)
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History
No history.
Information
Published : 2026-05-28 10:16
Updated : 2026-06-19 13:16
NVD link : CVE-2026-46196
Mitre link : CVE-2026-46196
CVE.ORG link : CVE-2026-46196
JSON object : View
Products Affected
linux
- linux_kernel
CWE