Low

Out-of-bounds access in Linux kernel ASoC Intel bytcr_rt5640 quirk input mapping

IdentifiersCVE-2025-40154CWE-129

CVE-2025-40154 is a Linux kernel vulnerability in the ASoC Intel bytcr_rt5640 driver. The flaw arises from improper handling of invalid quirk option values used for input mapping. When an unsupported or invalid value is supplied, the driver logs an error but leaves the invalid value in place instead of normalizing it to a safe default. This can result in unexpected behavior, including possible out-of-bounds memory access during subsequent processing of the quirk-derived mapping. The fix changes the driver behavior so that invalid input mapping values are corrected to a defined default value.

For your environment

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation may cause out-of-bounds access in kernel space, leading to memory corruption or a kernel crash and therefore denial of service. Because the flaw is in kernel code, any memory-safety consequence could also have broader confidentiality, integrity, or availability implications, although the available information does not confirm reliable privilege escalation or code execution for this specific issue.

Mitigation

If you can’t patch tonight, do this now.

No specific workaround is documented beyond applying the kernel update. Where immediate patching is not possible, reduce exposure by restricting the ability to supply or influence driver quirk parameters, limiting access to affected systems to trusted administrators, and minimizing opportunities for untrusted local users to interact with vulnerable kernel configuration paths.

Remediation

Patch, then assume compromise.

Update to a Linux kernel version containing the bytcr_rt5640 driver fix that validates invalid quirk input mapping values and replaces them with a safe default. On affected SUSE systems, install the vendor-provided kernel updates for the relevant product stream and reboot into the updated kernel.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

LinuxLinux Kerneloperating_system

Rocky LinuxRocky Linuxoperating_system

Rocky LinuxRocky Linux 8 Kernel-Rtoperating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

20 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.

20 SOURCESView more in app

No news coverage yet. Advisories and community discussion only.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity3