CVE-2026-64367 in Linux
Summary
by MITRE • 07/25/2026
In the Linux kernel, the following vulnerability has been resolved:
HID: hid-goodix-spi: validate report size to prevent stack buffer overflow
goodix_hid_set_raw_report() builds a protocol frame in a 128-byte stack buffer (tmp_buf), writing an 11-12 byte header followed by the caller-supplied report data. The HID core caps report size at HID_MAX_BUFFER_SIZE (16384) by default, while the driver does not set hid_ll_driver.max_buffer_size and performs no bounds checking before copying the payload:
memcpy(tmp_buf + tx_len, buf, len);
A hidraw SET_REPORT ioctl with a report larger than ~116 bytes overflows the stack buffer.
Add a size check after constructing the header, rejecting reports that would exceed the buffer capacity.
Discovered by Atuin - Automated Vulnerability Discovery Engine.
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Analysis
by VulDB Data Team • 07/25/2026
The vulnerability resides in the Linux kernel's HID subsystem, specifically within the goodix_hid_set_raw_report() function which handles SPI-based Goodix touchpad devices. This flaw represents a classic stack buffer overflow condition that occurs when processing HID report data through the hidraw interface. The driver allocates a 128-byte stack buffer named tmp_buf to construct protocol frames, with an 11-12 byte header followed by caller-supplied payload data. While the HID core layer properly enforces a maximum buffer size limit of 16384 bytes through HID_MAX_BUFFER_SIZE constant, the specific driver implementation fails to establish its own buffer size constraints by not setting hid_ll_driver.max_buffer_size. This omission creates a critical gap where user-supplied report data can overflow the fixed-size stack buffer without proper bounds checking before memory copying operations.
The operational impact of this vulnerability manifests when an attacker executes a hidraw SET_REPORT ioctl command with a report payload exceeding approximately 116 bytes. The memcpy operation that follows header construction directly copies the entire caller-provided buffer content into tmp_buf without validating whether the total frame size (header plus payload) exceeds the allocated stack buffer capacity. This condition allows for arbitrary stack memory corruption, potentially enabling privilege escalation or system instability depending on the execution context and memory layout. The vulnerability is particularly concerning because it operates at the kernel level within a driver that handles input device communications, making it accessible through standard HID interfaces.
This flaw aligns with CWE-121 Stack-based Buffer Overflow, which describes buffer overflow conditions where data written to a stack buffer exceeds its allocated size. The vulnerability also maps to ATT&CK technique T1068, which covers privilege escalation through local exploits. The discovery by Atuin - Automated Vulnerability Discovery Engine - demonstrates the effectiveness of automated analysis tools in identifying kernel-level security gaps that might otherwise remain undetected during traditional code reviews. The mitigation strategy involves implementing a size validation check immediately after header construction, specifically rejecting any report requests that would cause the combined header and payload to exceed the available buffer capacity. This approach follows established secure coding practices by enforcing bounds checking before memory operations and prevents the overflow condition from occurring in the first place.
The vulnerability represents a significant security risk for Linux systems utilizing Goodix touchpad devices through SPI interfaces, particularly in environments where untrusted users might have access to hidraw device controls. System administrators should prioritize applying kernel patches that implement the recommended size validation mechanism to prevent potential exploitation. The fix ensures that the driver maintains proper bounds checking while preserving functionality for legitimate use cases within acceptable size limits. This remediation aligns with secure development principles and helps maintain the integrity of kernel memory management operations, preventing unauthorized memory access patterns that could lead to privilege escalation or denial-of-service conditions affecting the entire system.