CVE-2024-26328
Description
A flaw was found in the NVMe emulation support of QEMU. The register_vfs() function in hw/pci/pcie_sriov.c does not set NumVFs to PCI_SRIOV_TOTAL_VF, causing the interaction with hw/nvme/ctrl.c to be mishandled. This issue could lead to out-of-bounds memory access in hw/nvme. This flaw allows a malicious guest to crash QEMU and cause a denial of service condition.
Statement
The affected code path can only be reached if dev->exp.sriov_cap is set. For example, if QEMU is explicitly launched with the hw/nvme SR-IOV emulation enabled (parameter sriov_max_vfs is set). The emulation is exclusively used to emulate NVMe devices with SR-IOV capabilities for host software development purposes. Thus, the security impact of this CVE is Low.
The qemu-kvm versions, as shipped with Red Hat Enterprise Linux and RHEL Advanced Virtualization, are not affected by this flaw as they did not include support for NVMe emulation.
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 | 4.7 | 6 | 6 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | High | High |
| User Interaction | None | None | None |
| Scope | Unchanged | Changed | Changed |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
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