CVE-2026-97975
Description
A flaw was found in the Linux kernel's Bluetooth subsystem. A race condition occurs when child network devices are unregistered concurrently while Bluetooth connection cleanup routines reparent child devices. A local user can exploit this timing issue to trigger a NULL pointer dereference, resulting in a kernel crash and a Denial of Service (DoS).
Statement
A race in Bluetooth hci_conn_del_sysfs can occur when a child device is being unregistered while the connection cleanup path reparents child devices. A BNEP network device can be removed from its parent klist by device_move while device_del still uses a stale parent state, resulting in a NULL pointer dereference in klist_put and a kernel crash. The missing explicit reference from the connection device to the HCI parent device also creates a stale device lifetime reference and an underlying use after free candidate. For the CVSS the PR:N is used because a nearby Bluetooth peer may trigger the affected BNEP connection and teardown activity without local code execution on the target. The attack vector is adjacent because Bluetooth communication requires radio proximity. The race requires timing control and therefore AC:H. Impact is at least denial of service via kernel crash and in the worst case may allow limited confidentiality or integrity impact due to the device lifetime use after free condition. This issue should be reviewed manually.
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 | 5.1 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | None | 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:N/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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