CVE-2022-48803 is a vulnerability identified in the Linux kernel, specifically within the PHY driver for Texas Instruments J721e hardware (phy-j721e-wiz.c). The issue arises from the function _get_table_maxdiv() attempting to access the clk_div_table array out of bounds due to a missing sentinel entry. This results in a global out-of-bounds memory access error, which was detected by the Kernel Address Sanitizer (KASAN). The vulnerability manifests as an out-of-bounds read of 4 bytes at an invalid memory address during the clock divider rate determination process. The bug is triggered during PHY initialization and PCIe PHY setup on affected hardware platforms. The root cause is the absence of a sentinel value in the clk_div_table array, which allows the function to read beyond the array boundary, potentially leading to undefined behavior or kernel crashes. The vulnerability affects Linux kernel versions containing the specific commit 091876cc355d6739e393efa4b3d07f451a6a035c and is related to the Texas Instruments J721e Evaluation Module (EVM) hardware. While no known exploits are reported in the wild, the issue can cause system instability or denial of service due to kernel panics or memory corruption. The vulnerability is primarily a software bug in the Linux kernel PHY driver code that requires patching to add the missing sentinel to the clk_div_table to prevent out-of-bounds access.

For European organizations, the impact of CVE-2022-48803 depends largely on the deployment of affected hardware platforms running the vulnerable Linux kernel versions, particularly those using Texas Instruments J721e-based systems. Such systems are often embedded or industrial devices, network equipment, or specialized computing platforms. The vulnerability can lead to kernel crashes or denial of service, which may disrupt critical infrastructure, industrial control systems, or network operations. Although there is no evidence of remote code execution or privilege escalation, the instability caused by out-of-bounds memory access can affect system availability and reliability. Organizations relying on embedded Linux devices in telecommunications, manufacturing, or automotive sectors may face operational interruptions. Additionally, the lack of a known exploit reduces immediate risk, but unpatched systems remain vulnerable to potential future exploitation or accidental crashes. Overall, the threat primarily impacts system availability and integrity, with limited direct confidentiality risks.

To mitigate CVE-2022-48803, organizations should: 1) Identify and inventory all Linux systems running on Texas Instruments J721e hardware or similar platforms that utilize the affected PHY driver. 2) Apply the official Linux kernel patches that add the missing sentinel entry to the clk_div_table array in phy-j721e-wiz.c as soon as they become available from trusted sources or Linux kernel maintainers. 3) For embedded or industrial devices where kernel updates are challenging, coordinate with device vendors or system integrators to obtain firmware or software updates addressing this vulnerability. 4) Implement robust monitoring for kernel panics or unusual system crashes that could indicate exploitation attempts or instability related to this vulnerability. 5) Employ network segmentation and access controls to limit exposure of vulnerable devices, reducing the risk of remote triggering of the bug. 6) Maintain regular backups and recovery procedures to minimize operational impact in case of system failures. 7) Engage in proactive vulnerability management to track updates from Linux kernel security advisories and promptly deploy patches.