CVE-2023-54057: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54057 is a buffer overflow vulnerability in the Linux kernel's IOMMU/AMD subsystem, specifically in the parse_ivrs_acpihid function. The flaw arises because the acpiid buffer can overflow due to a missing width limitation on the string specifier in an sscanf() format string when parsing the ivrs_acpihid kernel command-line parameter. It affects Linux kernel versions from 4.7 up to the patched stable releases (5.4.237, 5.10.175, 5.15.103, 6.1.16, 6.2.3, and 6.3). The vulnerability was discovered by InfoTeCS on behalf of the Linux Verification Center (linuxtesting.org) using the SVACE static analysis tool, and was published on December 24, 2025. The CVSS base score is listed as 0.0 in available databases, indicating the severity assessment is still pending or not yet assigned (Feedly, EUVD).

The root cause is a classic buffer overflow (CWE-120) in the parse_ivrs_acpihid function within the Linux kernel's iommu/amd driver. When the kernel parses the ivrs_acpihid command-line parameter at boot time, it uses sscanf() with a format string that lacks a width specifier for the %s token targeting the acpiid buffer, allowing an attacker-controlled string of arbitrary length to overflow the fixed-size buffer. Exploitation requires the ability to control kernel boot parameters (e.g., via physical access, bootloader manipulation, or a hypervisor/VM configuration interface), making this a local or privileged attack vector. The fix adds an explicit length limitation to the sscanf() format string to prevent the overflow (Feedly, EUVD).

Successful exploitation could allow an attacker with the ability to control kernel boot parameters to trigger a buffer overflow in kernel memory, potentially leading to kernel crashes (denial of service) or, in a worst-case scenario, arbitrary code execution at the kernel level. Because the vulnerability resides in the IOMMU/AMD subsystem, exploitation could undermine memory isolation guarantees provided by the IOMMU, potentially affecting the integrity and confidentiality of the entire system. The practical impact is constrained by the requirement to control boot parameters, limiting the attack surface primarily to physical access scenarios, VM environments, or systems with insecure bootloader configurations (Feedly, EUVD).

The Linux kernel maintainers have released patches across all affected stable branches. Users should update to the following patched versions or later: 5.4.237, 5.10.175, 5.15.103, 6.1.16, 6.2.3, or 6.3. The fix is identified by commits including 5e97dc748d13, f2a5ec7f7b28, c513043e0afe, 2ae19ac3ea82, 63cd11165e5e, and b6b26d86c61c in the stable kernel tree. As a workaround where patching is not immediately possible, restricting physical access to systems and securing bootloader configurations (e.g., using GRUB password protection) can reduce the risk of exploitation (Feedly, EUVD).