CVE-2023-21102: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-21102 is a vulnerability discovered in the __efi_rt_asm_wrapper of efi-rt-wrapper.S in the Linux kernel. The vulnerability stems from a logic error in the code that could potentially bypass shadow stack protection. This vulnerability was disclosed in May 2023 and affects Android kernel versions as well as various Linux distributions (NVD).

The vulnerability exists in the ARM64 EFI runtime services implementation of the Linux kernel, specifically in the __efi_rt_asm_wrapper function of efi-rt-wrapper.S. The issue involves improper management of concurrency calls that could lead to a bypass of shadow stack protection. The vulnerability has been assigned a CVSS v3.1 base score of 7.8 (High), with the vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (NVD).

The vulnerability could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not required for exploitation. A successful exploit could allow an attacker to cause a denial of service (system crash) or possibly execute arbitrary code (Ubuntu).

Multiple Linux distributions have released patches to address this vulnerability. Ubuntu has fixed the issue in various kernel versions including 5.19.0-42.43 for version 22.10 and 5.15.0-70.77 for version 22.04 LTS. Red Hat has addressed the vulnerability in their kernel-rt packages. Systems should be updated to the latest available kernel version that includes the security fix (Ubuntu, Red Hat).