CVE-2026-89747

A flaw was found in the Linux kernel's tracing component. A local attacker could exploit a use-after-free vulnerability, a type of memory corruption, by manipulating the trace_pipe functionality. This occurs when the system attempts to read from memory that has already been released, leading to unpredictable behavior. Successful exploitation could result in system instability or a denial of service.

A use after free can occur in the tracing trace_pipe read path when a reader keeps a pointer to a ring buffer event while another local actor changes buffer_subbuf_size_kb and replaces the ring buffer sub buffers. The reader can later dereference freed memory through ring_buffer_event_length() or ring_buffer_event_data(), which can cause a kernel crash and may expose stale kernel memory through trace output in a worst case interpretation. For the CVSS the PR:L is used for the paranoid score because tracefs access may be delegated to a non root local user or service account in some deployments. The issue is not network reachable and requires local interaction with tracing control files. Impact is at least local denial of service via kernel crash, with possible confidentiality impact from reading freed or reused kernel memory.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.