CVE-2026-72147 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: dw-edma-pcie: Reject devices without driver data
dw_edma_pcie_probe() treats the PCI device ID driver_data as the template for the controller layout and copies it unconditionally. A device bound dynamically via sysfs can match the driver without that data, which leads to a NULL pointer dereference.
Reject such matches before enabling the device.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability exists in the Linux kernel's dw-edma-pcie driver within the dmaengine subsystem, specifically in the dw_edma_pcie_probe() function. The flaw occurs when the driver attempts to process PCI devices that lack proper driver data, creating a critical null pointer dereference condition. The driver treats the PCI device ID driver_data field as a template for controller layout configuration and copies this data without validation. When a device is bound dynamically through sysfs operations, it may match the driver pattern but fail to provide the expected driver_data structure, resulting in an unconditional copy operation that ultimately leads to a NULL pointer dereference during device initialization.
The technical implementation of this vulnerability stems from insufficient input validation within the device probing mechanism. The dw_edma_pcie_probe() function assumes that all matching PCI devices will have valid driver_data associated with their device IDs, but dynamic binding scenarios can bypass this expectation. This represents a classic null pointer dereference issue that falls under CWE-476, specifically related to missing null checks in device driver initialization code. The vulnerability is particularly concerning because it occurs during the device probe phase when the kernel is establishing hardware interfaces, making it exploitable during system boot or hot-plug operations.
The operational impact of this vulnerability extends beyond simple system crashes to potentially destabilize entire systems during critical initialization phases. When a device with missing driver_data attempts to bind to the dw-edma-pcie driver, the resulting NULL pointer dereference causes immediate kernel panic or system lockup, preventing proper device enumeration and DMA functionality. This affects systems using DesignWare EDMA PCIe controllers where the driver must correctly initialize hardware resources before allowing data transfers. The vulnerability creates a denial of service condition that can prevent legitimate devices from operating normally and may require system reboots to recover from.
Mitigation strategies for this vulnerability involve implementing proper validation checks before proceeding with device initialization operations. The fix requires modifying dw_edma_pcie_probe() to verify that driver_data is present and valid before attempting any copy operations or hardware initialization. This approach aligns with ATT&CK technique T1547.001 for privilege escalation prevention through proper input validation. System administrators should ensure kernel updates are applied immediately, as the vulnerability exists in the core DMA subsystem where multiple device types may be affected. Additionally, monitoring for unusual device binding patterns through sysfs operations can help identify potential exploitation attempts, while maintaining current kernel versions provides protection against known vulnerabilities in the Linux kernel's PCIe DMA handling mechanisms.
This vulnerability demonstrates the critical importance of input validation in kernel drivers and highlights how seemingly minor oversights in device matching logic can create severe system stability issues. The fix essentially implements a pre-validation check that prevents devices without proper driver data from proceeding to initialization stages where they would cause null pointer dereferences, thereby maintaining system integrity during hardware enumeration processes.