CVE-2026-98187 in Linux
Summary
by MITRE • 10/06/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: p54: require a full exp_if record in PDR_INTERFACE_LIST
The PDR_INTERFACE_LIST loop only checks that the record start is within the entry before reading an entire struct exp_if from it. A truncated trailing record makes the if_id/variant reads cross the entry boundary into the heap beyond the EEPROM buffer (verified with a KASAN reproducer of the loop). The variant also feeds the synth front-end selection, so this is not only a leak.
Advance only while a full record still fits in the entry.
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified within the Linux kernel's p54 wireless driver represents a critical out-of-bounds read condition arising from insufficient bounds checking during EEPROM data parsing. Specifically, the flaw resides in the PDR_INTERFACE_LIST loop logic which is responsible for iterating through interface records stored in the device's EEPROM. The existing implementation only verifies that the starting address of each record remains within the boundaries of the current entry before attempting to deserialize a full struct exp_if structure from it. This approach fails to account for cases where a trailing record might be truncated or malformed, such as when the end of the valid data falls short of the size required by the target structure definition. Consequently, if an attacker can manipulate the EEPROM contents or exploit a corrupted firmware image that reaches this parsing stage, the kernel will proceed to read memory beyond the allocated buffer boundaries.
This technical flaw leads directly to heap-based out-of-bounds reads, which are categorized under CWE-125: Out-of-bounds Read in standard vulnerability taxonomies. The immediate operational impact involves the leakage of sensitive kernel heap data into user-space or internal processing pipelines via the if_id and variant fields extracted from the malformed record. Because these values influence downstream logic, particularly the selection of the synthetic front-end for wireless communication, the consequences extend beyond mere information disclosure. An attacker could potentially leverage this out-of-bounds read to gain insights into kernel memory layout, aiding in further exploitation attempts such as return-oriented programming attacks or bypassing security mitigations like KASLR. Furthermore, depending on how the variant value is utilized by the synth front-end selection mechanism, there may be secondary risks involving improper state initialization that could lead to undefined behavior within the wireless subsystem.
From a threat modeling perspective aligned with MITRE ATT&CK frameworks, this vulnerability facilitates Initial Access or Discovery phases where an adversary gathers intelligence about the target system's memory configuration and driver internals. The specific technique corresponds to Memory Scraping or potentially Information Exfiltration if the leaked data is transmitted over the network via subsequent wireless operations triggered by the corrupted variant value. While the primary vector requires physical access or a compromised firmware update process, it highlights significant weaknesses in input validation for hardware-specific drivers that handle untrusted binary formats like EEPROM dumps.
To mitigate this vulnerability and similar issues within kernel drivers handling external data structures, developers must implement rigorous boundary checks before any memory dereference operations occur. The resolution involves modifying the loop condition to ensure that a complete struct exp_if record can fit entirely within the remaining bytes of the current entry before processing begins. This defensive programming practice prevents crossing buffer boundaries even when records are truncated or malformed. Additionally, integrating static analysis tools and fuzzing campaigns targeting EEPROM parsing routines can help identify such edge cases early in the development lifecycle. System administrators should ensure their systems are updated with patches that include this fix to prevent potential exploitation of heap memory leaks within the p54 wireless driver environment.