CVE-2023-53634
Description
A control-flow integrity flaw was found in the Linux kernel on the arm64 architecture within the extended Berkeley Packet Filter trampoline return path. Returning to a patched function with an instruction sequence that fails the branch-target security check can trigger an exception and panic.
A local user could use this flaw to crash the system when attaching programs that patch kernel call sites, resulting in a denial of service.
Statement
When the trampoline is configured to call the original function, it used an indirect branch back to the instruction after the call site. On arm64 systems with branch target enforcement, if that instruction is not one of the expected landing pads, the hardware raises an exception. The fix switches to a return instruction so the hardware recognizes a valid return target.
Mitigation
To mitigate this issue, prevent module bpf from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
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).
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
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