CVE-2024-46859

What it actually does

Out-of-bounds read/write access to the SINF array in the panasonic-laptop kernel driver when the array contains fewer than 0x0e entries on certain hardware models, allowing invalid memory accesses in probe, resume, and sysfs handlers.

Why it matters to the business

Local users on affected Panasonic laptops can trigger kernel memory corruption leading to crashes, privilege escalation, or system compromise; organizations running Linux on these devices face increased risk of downtime and unauthorized access until updated kernels are deployed.

How an attack unfolds

An attacker with local access loads or triggers the panasonic-laptop module on a device whose ACPI SINF table is undersized; the driver then indexes beyond the array bounds during brightness or mute operations without validation, resulting in out-of-bounds memory access that can be leveraged for further kernel exploitation.

How to fix it

Update to a kernel containing commit b7c2f692307fe704be87ea80d7328782b33c3cef or later; ensure the panasonic-laptop driver refuses to load on undersized SINF arrays and applies bounds checks before sysfs attribute access.

How to confirm the fix worked

Verify the running kernel contains the fix commit, confirm the driver module rejects undersized SINF tables at probe time, and test that sysfs attributes are hidden or safely bounded on affected hardware models.

Typical attack path

1. Obtain local user access on a vulnerable Panasonic laptop model
2. Trigger loading of the panasonic-laptop driver (via hardware presence or manual modprobe)
3. Perform operations that invoke SINF array accesses (brightness changes or sysfs reads/writes)
4. Exploit resulting out-of-bounds memory access for privilege escalation or denial of service

How to detect it

Inspect kernel logs for panasonic-laptop probe failures or out-of-bounds warnings, review dmesg output during module load on affected hardware, and search system audit logs for unexpected sysfs accesses to brightness or mute attributes.

What your security team should do

• Prioritize kernel updates on all Panasonic laptop fleets within the next patching cycle
• Audit systems for presence of the panasonic-laptop driver and restrict module loading where possible
• Monitor vendor firmware and kernel changelogs for additional related panasonic-laptop fixes