CVE-2026-97416
Description
A flaw was found in the Linux kernel's Btrfs file system. An attacker could exploit this vulnerability by mounting a corrupted file system image and initiating a balance operation. Due to a missing validation check when querying block group metadata, the kernel triggers a null pointer dereference and crashes, resulting in a Denial of Service (DoS).
Statement
A low impact NULL pointer dereference flaw was found in the Linux kernel's Btrfs file system implementation. When a corrupted filesystem image contains a chunk item in the chunk tree without a corresponding block group in the in-memory cache, running a Btrfs balance operation causes btrfs_may_alloc_data_chunk() to dereference the NULL pointer returned by btrfs_lookup_block_group(), crashing the kernel and resulting in a local denial of service. There is no impact to confidentiality or integrity. Exploitation requires local access with the privileges needed to mount a crafted Btrfs filesystem image and issue the balance ioctl (for example CAP_SYS_ADMIN), which limits the practical severity, and Red Hat therefore rates the overall impact of this flaw as Low. The currently affected Red Hat products are the Red Hat Enterprise Linux 10 kernel and the Red Hat In-Vehicle OS 2 kernel offerings; for these streams the fix is deferred to a future update, and the residual risk is limited to a local denial of service that requires an already-corrupted filesystem image and privileged administrative action. Red Hat Enterprise Linux 7, 8, and 9 (including the kernel-rt packages) and the OpenShift Container Platform RHEL CoreOS images are not affected because the vulnerable code is not present in those releases, and the Red Hat Enterprise Linux 6 Extended Lifecycle Support kernel is out of support scope for this flaw.
Mitigation
Mitigation for this issue is either not available or the currently available options do not 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 | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | 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:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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