CVE-2026-98053: Linux Kernel Buffer Overflow Vulnerability

CVE-2026-98053 Overview

CVE-2026-98053 is an out-of-bounds read vulnerability in the Linux kernel's ASoC (ALSA System on Chip) Intel AVS driver. The flaw resides in how avs_path_module_send_init_configs() accesses entries in the ->init_configs array using indexes stored in the ->config_ids array. The two arrays are bounded by distinct counters, ->num_init_configs and ->num_config_ids, allowing an ID value equal to or greater than ->num_init_configs to trigger out-of-bounds memory access during audio topology processing.

Critical Impact
Loading a malformed audio topology can cause kernel out-of-bounds memory access in the Intel AVS ASoC driver, potentially leading to kernel memory disclosure or system instability.

Affected Products

Linux kernel versions containing the Intel AVS ASoC driver prior to the fix
Systems using Intel Audio DSP (AVS) audio topology files
Distributions shipping affected stable kernel branches referenced in the upstream commits

Discovery Timeline

2026-09-25 - CVE-2026-98053 published to NVD
2026-09-30 - Last updated in NVD database

Technical Details for CVE-2026-98053

Vulnerability Analysis

The vulnerability affects the Intel AVS (Audio Voice Smart) driver within the Linux kernel's ASoC subsystem. The driver processes audio topology files that describe module configurations for the audio DSP. During initialization, the kernel iterates over module config IDs and uses those IDs to index into a separate init_configs array.

The two arrays have independent length bounds. When an ID in ->config_ids is greater than or equal to ->num_init_configs, the dereference &acomp->tplg->init_configs[ids[i]] reads memory outside the allocated init_configs buffer. The upstream fix refactors the code to store direct pointers to the actual config entries rather than indexes, and reuses the existing topology validation path.

Root Cause

The root cause is missing bounds validation between two related but independently sized arrays. The topology loader validated the length of ->config_ids but did not confirm that each ID value remained within the range of ->init_configs. This classifies as an Out-of-Bounds Read, and in refactored paths an improper input validation issue in topology parsing.

Attack Vector

Exploitation requires the system to load a crafted or corrupted audio topology file through the Intel AVS driver. This typically requires local privileges capable of influencing firmware/topology loading, or physical control over the device supplying the topology blob. The out-of-bounds read occurs in kernel space and can leak adjacent kernel memory contents or cause instability depending on the memory layout surrounding the init_configs allocation.

See the upstream fix commits for technical details: Kernel Git Commit 681e910, Kernel Git Commit 75bd5ea, and Kernel Git Commit 8f20a0f.

Detection Methods for CVE-2026-98053

Indicators of Compromise

Kernel log entries referencing avs_path_module_send_init_configs with abnormal values or faults.
KASAN or similar sanitizer reports of out-of-bounds reads in the snd-soc-avs module.
Unexpected audio subsystem failures or kernel oops entries on Intel AVS-equipped hardware after topology loading.

Detection Strategies

Audit loaded audio topology files on Intel platforms and verify integrity against known-good vendor-signed blobs.
Enable KASAN in test or staging kernels to surface out-of-bounds access patterns during topology load.
Monitor kernel ring buffer output (dmesg) for warnings tied to the ASoC avs driver during boot and runtime.

Monitoring Recommendations

Collect kernel logs centrally and alert on messages originating from snd_soc_avs or avs_path_* symbols.
Track installed kernel package versions across the Linux fleet and compare against patched stable releases.
Monitor file integrity for /lib/firmware/intel/avs/ topology files to detect tampering.

How to Mitigate CVE-2026-98053

Immediate Actions Required

Apply the vendor-supplied kernel update that incorporates the upstream fix commits for the Intel AVS init_config access path.
Inventory systems using the snd_soc_avs module and prioritize patching endpoints with Intel audio DSP hardware.
Restrict local user ability to supply arbitrary topology or firmware files to the kernel.

Patch Information

The fix is available in the upstream Linux stable tree through commits 681e910, 75bd5ea, and 8f20a0f. The patch refactors init_config handling to store direct pointers to config entries and reuses existing topology validation, eliminating the out-of-bounds index dereference.

Workarounds

Blacklist the snd_soc_avs module on systems that do not require Intel AVS audio functionality until the kernel is patched.
Enforce signed firmware and topology loading policies via CONFIG_FW_LOADER_USER_HELPER restrictions and vendor-provided integrity controls.
Limit local account privileges that could be used to supply or modify audio topology files.

bash

# Temporarily disable the Intel AVS ASoC driver pending patch deployment
echo "blacklist snd_soc_avs" | sudo tee /etc/modprobe.d/blacklist-avs.conf
sudo update-initramfs -u
# Verify the module is not loaded after reboot
lsmod | grep snd_soc_avs