CVE-2023-54245: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54245 is a slab-out-of-bounds read vulnerability in the Linux kernel's ASoC (Audio System on Chip) tx-macro codec driver. The flaw was discovered via syzkaller fuzzing and triggers a KASAN (Kernel Address Sanitizer) report: "slab-out-of-bounds Read in regcache_flat_read". It affects Linux kernel versions from the initial commit up to fixed releases in stable branches (patched in 5.15.106, 6.1.23, 6.2.10, and 6.3). The vulnerability was formally published on December 30, 2025, and carries an EPSS score of approximately 0.025% (very low), with no CVSS base score assigned by the assigner (Feedly, EUVD).

The root cause is an incorrect data type used for the decimator variable in the tx_macro_digital_mute() function within sound/soc/codecs/tx-macro.c. The variable was declared with a 32-bit type, causing it to be used as an index into a register cache (regcache_flat_read) that exceeds the allocated bounds when the value is large. This is classified as CWE-125 (Out-of-bounds Read). The fix constrains the variable to a u8 (8-bit unsigned integer) type, preventing out-of-bounds access. The issue was surfaced through syzkaller-based kernel fuzzing and confirmed via KASAN instrumentation (Feedly, EUVD).

Exploitation of this vulnerability results in an out-of-bounds read in kernel memory, which could lead to information disclosure of sensitive kernel data or a kernel panic causing a denial of service. Because the flaw resides in a kernel audio codec driver, it is most relevant to systems with Qualcomm-based audio hardware (e.g., mobile or embedded Linux devices using the tx-macro codec). There is no evidence of privilege escalation or remote code execution potential based on available information (Feedly).

The fix has been backported to multiple stable Linux kernel branches. Users should upgrade to kernel version 5.15.106 or later (5.15.x branch), 6.1.23 or later (6.1.x branch), 6.2.10 or later (6.2.x branch), or 6.3 or later (mainline). The patches are available in the Linux stable kernel repository. No configuration-based workaround is documented; upgrading to a patched kernel version is the recommended remediation (EUVD, Feedly).