CVE-2026-46079
Description
A flaw was found in the Linux kernel's Rados Block Device (rbd) module. When adding a new block device, a double teardown of resources can occur if the disk addition process fails. This can lead to a null-pointer dereference during cleanup operations, allowing a local attacker to cause a system crash, resulting in a Denial of Service (DoS).
Statement
A Moderate flaw exists in the Linux kernel's Rados Block Device (rbd) module. This vulnerability stems from a double teardown of resources during the failure of a new block device addition, which can result in a null-pointer dereference. A local attacker could leverage this to trigger a system crash, leading to a Denial of Service on Red Hat Enterprise Linux 9 and Red Hat In-Vehicle OS 2 systems where the rbd module is in use.
Mitigation
If the Rados Block Device (rbd) module is not required, it can be prevented from loading to mitigate this issue.
To blacklist the `rbd` module, create a configuration file:
`echo "blacklist rbd" | sudo tee /etc/modprobe.d/disable-rbd.conf`
Then, regenerate the initramfs and reboot the system for the change to take effect:
`sudo dracut -f -v` (for systems using dracut)
`sudo reboot`
This action will disable functionality dependent on the `rbd` module, such as Ceph Rados Block Devices.
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 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: 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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