CVE-2026-43182: Linux Kernel Division by Zero Vulnerability

CVE-2026-43182 Overview

CVE-2026-43182 is a division by zero vulnerability in the Linux kernel's Common Camera Sensor (CCS) media driver. The flaw resides in the scaler configuration logic, where the driver calculates the maximum M value by dividing by the MIN_X_OUTPUT_SIZE limit register's value. The driver assumed this register value would always be non-zero but did not enforce that assumption. When the register returns zero, the division operation triggers a kernel-level fault. The Linux kernel maintainers have resolved the issue through a series of stable tree commits.

Critical Impact

A division by zero in kernel space can trigger a denial of service condition affecting system stability on hosts using the CCS media subsystem.

Affected Products

• Linux kernel media/ccs driver
• Systems using Common Camera Sensor (CCS) compatible hardware
• Multiple stable kernel branches receiving backported fixes

Discovery Timeline

• 2026-05-06 - CVE-2026-43182 published to NVD
• 2026-05-06 - Last updated in NVD database

Technical Details for CVE-2026-43182

Vulnerability Analysis

The vulnerability exists in the CCS driver's scaler configuration routine within the Linux kernel media subsystem. The driver computes the maximum M parameter for the scaler by dividing an input value by the contents of the MIN_X_OUTPUT_SIZE limit register. The CCS specification presumes this register holds a non-zero value, but the driver did not validate the assumption before performing arithmetic. A zero value triggers a divide-by-zero fault in kernel context. This results in a kernel oops or panic depending on configuration. Hardware returning unexpected register values, faulty sensors, or maliciously crafted device responses can all reach this code path.

Root Cause

The root cause is missing input validation on a hardware-supplied register value before its use as a divisor. The driver trusted the MIN_X_OUTPUT_SIZE limit register without confirming the value was non-zero. This represents an Improper Input Validation pattern affecting kernel arithmetic operations.

Attack Vector

The attack vector requires interaction with a CCS-compatible camera sensor or a controllable hardware interface that supplies the limit register value. Triggering the condition typically requires local access or physical access to attach affected hardware. Successful triggering causes a kernel division fault leading to denial of service.

The fix adds an explicit check that rejects a zero value before the division operation. Refer to the upstream patch commits for the validation logic. See Linux Kernel Commit 32a21ed and Linux Kernel Commit c9af181 for the patch details.

Detection Methods for CVE-2026-43182

Indicators of Compromise

• Kernel oops or panic logs referencing ccs driver functions and divide error exceptions
• Unexpected system reboots on hosts with CCS-compatible camera sensors attached
• dmesg output showing arithmetic exception traces originating from the media subsystem

Detection Strategies

• Monitor kernel log entries for divide-by-zero faults associated with the media/ccs module
• Audit running kernel versions across Linux fleets to identify hosts on unpatched stable branches
• Track hardware enumeration events for CCS sensors paired with subsequent kernel exceptions

Monitoring Recommendations

• Forward /var/log/kern.log and journalctl -k output to a centralized log platform for correlation
• Alert on kernel panic events involving the media subsystem on production Linux hosts
• Maintain an inventory of kernel versions and CCS driver status across endpoints

How to Mitigate CVE-2026-43182

Immediate Actions Required

• Apply the upstream stable kernel update containing the CCS division-by-zero fix
• Identify hosts loading the ccs kernel module and prioritize patching them first
• Restrict physical access to systems that interface with CCS-compatible camera hardware

Patch Information

The Linux kernel maintainers released the fix across multiple stable branches. Apply the appropriate update from the kernel.org stable tree. Relevant commits include Linux Kernel Commit 679f0b7, Linux Kernel Commit 8ca7df1, Linux Kernel Commit 9aae0f3, Linux Kernel Commit a8ff58c, and Linux Kernel Commit b6e0529.

Workarounds

• Blacklist the ccs kernel module on systems that do not require CCS camera support
• Disable or unbind affected CCS devices through the sysfs interface where feasible
• Limit user-space utilities that can probe or initialize the media subsystem to trusted accounts

# Blacklist the ccs module to prevent loading until patched
echo "blacklist ccs" | sudo tee /etc/modprobe.d/blacklist-ccs.conf
sudo update-initramfs -u

# Verify current kernel version against patched stable releases
uname -r