CVE-2026-97938
Description
A flaw was found in the Linux kernel. A race condition in the reboot management subsystem allows a process identifier reference to be released while still being accessed by concurrent operations. A local attacker could exploit this use-after-free flaw to cause a Denial of Service (DoS) via a system crash or potentially escalate privileges.
Statement
A use-after-free race exists in the global cad_pid pointer handling. proc_do_cad_pid can pass a stale struct pid pointer to pid_vnr and kill_cad_pid can pass the same stale pointer to kill_pid while a concurrent sysctl writer replaces cad_pid and drops the final reference to the old pid object. The race can cause a kernel crash or incorrect PID object handling. For the CVSS the PR:H is used because reliably changing the global cad_pid sysctl normally requires administrator privileges in the initial user namespace. The issue is local and is not directly network reachable. The confirmed bug class is use-after-free. Limited confidentiality and integrity impact are retained only for the paranoid score because freed pid memory could be reused before dereference.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.1 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | High | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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