CVE-2026-23369 in Linux
Riassunto
di VulDB • 21/06/2026
Based on the kernel call trace provided, here is an analysis of the issue, its root cause, and potential solutions.
### **Summary** The system experienced a **Page Fault** (likely a NULL pointer dereference or invalid memory access) while the kernel was trying to read the state of the **AC adapter** via ACPI. The crash occurred in the `i2c_i801` driver's ACPI I/O handler, which is used by the Intel ICH/LPC/eSPI controller to access SMBus/ACPI registers.
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### **Detailed Analysis**
#### **1. The Crash Point** ``` [ 14.972045] ? i801_acpi_io_handler+0x2d/0xb0 [i2c_i801]
[ 14.972061] acpi_ev_address_space_dispatch+0x16e/0x3c0
``` - The crash happened inside `i801_acpi_io_handler`, a function in the `i2c_i801` kernel module. - This handler is registered by the `i2c_i801` driver to allow ACPI to access hardware resources (like SMBus) through the Intel I801 SMBus controller. - The `?` prefix indicates this is where the fault occurred, likely due to an invalid memory access (e.g., dereferencing a NULL pointer or accessing unmapped memory).
#### **2. The Trigger** ``` [ 14.972181] acpi_ac_get_state.part.0+0x23/0x70
[ 14.972189] get_ac_property+0x4e/0x60
[ 14.972195] power_supply_show_property+0x90/0x1f0
[ 14.972205] add_prop_uevent+0x29/0x90
[ 14.972213] power_supply_uevent+0x109/0x1d0
``` - The kernel was processing a **uevent** (device event) for the power supply subsystem. - Specifically, it was trying to read the `state` property of the AC adapter (`acpi_ac_get_state`). - This is typically triggered when userspace reads `/sys/class/power_supply/AC*/uevent` or when the power supply subsystem updates its status.
#### **3. The Root Cause** The `i2c_i801` driver's ACPI handler (`i801_acpi_io_handler`) is being called to access an ACPI region, but it is failing. Common reasons include: 1. **Driver Conflict**: The `i2c_i801` driver may be loaded, but the ACPI namespace does not correctly map to the SMBus controller, or the controller is in a state where it cannot respond. 2. **NULL Pointer**: The handler may be dereferencing a pointer that was not properly initialized (e.g., `priv` or `data` pointer in the handler context). 3. **Hardware/BIOS Bug**: The ACPI tables (DSDT/SSDT) may define an ACPI region that uses the SMBus controller, but the hardware does not support it or is misconfigured. 4. **Race Condition**: The driver may be unloaded or reinitialized while ACPI is still trying to access it.
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### **Solutions & Workarounds**
#### **1. Blacklist the `i2c_i801` Driver (Temporary Fix)** If the system is stable otherwise, you can prevent the `i2c_i801` driver from loading. This will stop the crash but may disable SMBus functionality (e.g., sensor readings, some battery charging features).
- **Create a blacklist file**: ```bash echo "blacklist i2c_i801" | sudo tee /etc/modprobe.d/blacklist-i2c_i801.conf ``` - **Update initramfs** (if applicable): ```bash sudo update-initramfs -u # Debian/Ubuntu sudo dracut -f # RHEL/CentOS/Fedora ``` - **Reboot**.
#### **2. Update Kernel and BIOS** - **Kernel Update**: This issue may have been fixed in newer kernel versions. Check if a newer LTS or mainline kernel resolves the problem. - **BIOS Update**: Manufacturers often fix ACPI table bugs in BIOS updates. Check your motherboard/laptop manufacturer's website for the latest BIOS.
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