CVE-2023-52930
Description
A flaw was found in the Linux kernel's Intel graphics driver (i915), specifically within the Direct Rendering Manager (DRM) subsystem. This issue arises when multiple threads simultaneously attempt to set the tiling mode of a graphics buffer to I915_TILING_NONE using the I915_GEM_SET_TILING ioctl. These concurrent operations can lead to a race condition, resulting in a double-free of the bit_17 bitmask or a memory leak during the transition to a tiled mode. The root cause is the lack of proper synchronization when allocating and freeing the bitmask, leading to potential memory corruption and system instability.
Statement
The vulnerability occurs in the i915 driver when using the DRM_IOCTL_I915_GEM_SET_TILING ioctl, which is only accessible to processes with sufficient privileges to open /dev/dri/* (the DRM device). Access to this device node is not granted to unprivileged users by default on most systems.
Exploiting this vulnerability typically requires elevated privileges unless one of the following occurs:
- The system is configured to allow unprivileged users to access the DRM device node (for example, through udev rules or group membership like video),
- Or the process is already running with elevated privileges (for example, root).
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 | 6.7 | 7.8 | 7.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | High | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
A successful exploitation of this flaw requires the attacker to have root-level privileges, which is why the CVSS has been marked as such.
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
When a program calls free() twice with the same argument, the program's memory management data structures may become corrupted, potentially leading to the reading or modification of unexpected memory addresses. This corruption can cause the program to crash or, in some circumstances, cause two later calls to malloc() to return the same pointer. If malloc() returns the same value twice and the program later gives the attacker control over the data that is written into this doubly-allocated memory, the program becomes vulnerable to a buffer overflow attack. Doubly freeing memory may result in a write-what-where condition, allowing an attacker to execute arbitrary code.
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