CVE-2026-64349 in Linux
Summary
by MITRE • 07/25/2026
In the Linux kernel, the following vulnerability has been resolved:
usb: dwc3: fix dwc3_readl() and dwc3_writel() calls in dwc3_ulpi_setup()
The dwc3_ulpi_setup() calls the register read and write calls with dwc3->regs when both these calls take the dwc3 structure directly.
Chnage these two calls to fix the following sparse warning, and possibly a nasty bug in the dwc3_ulpi_setup() code:
drivers/usb/dwc3/core.c:796:45: warning: incorrect type in argument 1 (different address spaces) drivers/usb/dwc3/core.c:796:45: expected struct dwc3 *dwc drivers/usb/dwc3/core.c:796:45: got void [noderef] __iomem *regs
drivers/usb/dwc3/core.c:798:40: warning: incorrect type in argument 1 (different address spaces) drivers/usb/dwc3/core.c:798:40: expected struct dwc3 *dwc drivers/usb/dwc3/core.c:798:40: got void [noderef] __iomem *regs
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Analysis
by VulDB Data Team • 07/25/2026
The vulnerability resides in the Linux kernel's usb dwc3 driver where a critical type mismatch occurs in the dwc3_ulpi_setup() function. This issue stems from improper handling of memory address spaces when performing register read and write operations within the USB device controller driver. The problem manifests as incorrect argument types being passed to dwc3_readl() and dwc3_writel() functions, creating a fundamental conflict between expected and actual parameter signatures.
The technical flaw involves a fundamental mismatch in how the dwc3 structure's registers are accessed during the ULPI (Universal Low Pin Interface) setup process. When dwc3_ulpi_setup() executes, it attempts to call dwc3_readl() and dwc3_writel() functions with dwc3->regs as an argument, but these functions expect a struct dwc3 dwc parameter instead of the direct register pointer. This type inconsistency creates a sparse warning indicating different address spaces between expected and actual arguments, specifically showing that the function expects a struct dwc3 dwc but receives a void __iomem *regs pointer.
This vulnerability represents a serious operational risk within embedded systems and USB device controllers that rely on the DesignWare USB 3.0 controller implementation. The incorrect memory addressing pattern could lead to unpredictable behavior during USB initialization, potentially causing system crashes, data corruption, or complete USB functionality failures. The issue affects the core USB controller driver's ability to properly configure and initialize USB interfaces, particularly those using ULPI physical layer interfaces.
The security implications extend beyond simple operational reliability concerns as this type of memory access error could create potential attack vectors for privilege escalation or denial-of-service conditions. According to CWE classification, this vulnerability maps to CWE-467: Use of sizeof() on a Pointer Type, though more specifically relates to improper pointer handling and address space confusion. The flaw also connects to ATT&CK technique T1068: Exploitation for Privilege Escalation through kernel-level memory corruption vulnerabilities.
The fix requires modifying the dwc3_ulpi_setup() function to properly handle the register access by correcting the parameter passing mechanism between the dwc3 structure and the register read/write functions. This ensures that the correct data types are passed to dwc3_readl() and dwc3_writel() calls, eliminating the sparse warnings and preventing potential runtime errors during USB controller initialization. The mitigation strategy involves ensuring proper kernel memory mapping and address space handling throughout the USB device controller driver implementation.
System administrators and embedded developers should prioritize updating affected kernel versions to prevent potential exploitation of this vulnerability in production environments. The fix addresses the root cause by properly aligning the expected parameter types with actual argument values, thereby maintaining proper USB controller functionality and preventing potential system instability or security compromise during USB device enumeration processes.