CVE-2026-90112 in Linux
Summary
by MITRE • 09/17/2026
In the Linux kernel, the following vulnerability has been resolved:
net: qlcnic: validate unified ROM sections before loading
The unified ROM parser reads directory, product, and data-descriptor fields from the firmware file. Existing validation forms table and data ends with unchecked additions and multiplications. Malformed values can wrap before they are compared with the firmware size. The parser also dereferences typed pointers at firmware-controlled offsets.
Valid descriptor extents alone are insufficient for the consumers. The loader reads a fixed-size bootloader regardless of its declared size, the version parser assumes a 17-byte tail, and a partial final firmware word is read as a full u64. A truncated image can therefore make the driver read beyond the firmware allocation during validation or loading.
Replace the pointer-returning parser with bounded range helpers. Validate table entry sizes, descriptor indices, section ranges, the fixed bootloader load length, and the version tail before exposing any section. Read all file fields with unaligned little-endian accessors and assemble a partial final word from only the bytes that remain. Apply the same range checks to the legacy image before reading its fixed fields.
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Analysis
by VulDB Data Team • 09/17/2026
The Linux kernel network driver for QLogic NICs, specifically qlcnic, contained critical memory safety vulnerabilities within its unified ROM parser logic. This component is responsible for parsing directory, product, and data-descriptor fields from firmware files to initialize hardware correctly. The core technical flaw stemmed from insufficient validation of arithmetic operations during the parsing process. Specifically, existing checks failed to account for integer overflow conditions in table size calculations and data offset multiplications. When a maliciously crafted or corrupted firmware image is provided, these unchecked mathematical operations can result in value wrapping due to signed integer overflow before the resulting offsets are compared against the total firmware file size. This logical error allows an attacker to bypass boundary checks that would otherwise prevent access to memory regions outside the allocated buffer space.
Beyond the arithmetic validation failures, the driver exhibited unsafe pointer dereferencing behavior based on values controlled by the input firmware data. The parser directly used offsets derived from the firmware image as pointers without rigorous bounds checking against valid descriptor extents. Furthermore, several downstream consumers of this parsed data assumed fixed structural properties that do not always hold true for all firmware images. For instance, the bootloader loader reads a fixed-size block regardless of what size is declared in the file headers, and the version parser assumes the presence of a specific 17-byte tail section. Additionally, when reading the final word of a firmware image, if fewer than eight bytes remain, the code incorrectly assembles this partial data into a full u64 value rather than handling it safely. These assumptions mean that even if basic range checks pass for certain sections, truncated or malformed images can still cause the driver to read beyond the allocated memory boundaries during validation and loading phases.
The operational impact of these vulnerabilities is severe, primarily manifesting as out-of-bounds reads which constitute a classic buffer over-read condition. An attacker who can influence the firmware image loaded by the system could exploit this flaw to leak sensitive kernel memory contents into user space or trigger a denial of service through a kernel panic caused by accessing unmapped pages. This vulnerability aligns with CWE-190, Integer Overflow or Wraparound, and CWE-787, Out-of-bounds Read, within standard classification systems. In the context of the MITRE ATT&CK framework, this represents an initial access vector where malicious firmware is used to execute unauthorized code or gather intelligence from kernel memory via information disclosure techniques such as T1056.
To remediate these issues, the vulnerability was resolved by replacing the pointer-returning parser with bounded range helpers that enforce strict limits on all accessed data structures. The fix involves validating table entry sizes, descriptor indices, and section ranges before any part of a firmware section is exposed to higher-level drivers. Developers implemented checks for fixed bootloader load lengths and version tail requirements to ensure structural integrity matches expectations. Crucially, the code was updated to use unaligned little-endian accessors for reading file fields, ensuring correct data interpretation across different architectures. The logic for handling partial final words was corrected to assemble values only from the bytes that actually remain in the buffer, preventing garbage data inclusion or out-of-bounds reads. These same rigorous range checks were also applied to legacy image formats to ensure comprehensive protection against malformed inputs during both validation and loading processes.