CVE-2024-46739
Description
A flaw was found in the Linux kernel. A local attacker with low privileges could trigger a null pointer dereference in the uio_hv_generic module's hv_uio_rescind function. This occurs when the system attempts to access a memory location that is not properly assigned for primary VM Bus channels. Successful exploitation of this vulnerability could lead to a system crash, resulting in a Denial of Service (DoS).
Mitigation
To prevent the uio_hv_generic kernel module from loading, create a blacklist entry.
bashAfter applying this change, regenerate the initramfs and reboot the system for the mitigation to take effect.
echo "blacklist uio_hv_generic" | sudo tee /etc/modprobe.d/blacklist-uio_hv_generic.conf
bashThis action may affect systems utilizing User-space I/O for Hyper-V virtual machines.
sudo dracut -f -v
sudo reboot
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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