CVE-2026-68196 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: validate assoc response length before subtracting header
wilc_parse_assoc_resp_info() computes the trailing IE length as
ies_len = buffer_len - sizeof(*res);
without first checking that buffer_len is at least sizeof(struct wilc_assoc_resp) (6 bytes). buffer_len is the length reported for a received association response (host_int_parse_assoc_resp_info() passes hif_drv->assoc_resp / assoc_resp_info_len straight in) and must be validated before the driver accesses the fixed header.
For a frame shorter than the 6-byte fixed header, the subtraction wraps. For a four-byte response the result is truncated to a u16 ies_len of 65534, so kmemdup() then attempts to copy 65534 bytes starting at buffer + sizeof(*res), beyond the valid association-response data (CWE-125). A response shorter than four bytes can also cause an out-of-bounds read of res->status_code at offsets 2 and 3.
Reject frames too short to hold the fixed header before touching the header or computing ies_len. Also set the connection status to a failure on this path: the caller falls through to a "conn_info->status == WLAN_STATUS_SUCCESS" check after the parser returns, so leaving the status untouched could let a malformed short response be treated as a successful association.
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Analysis
by VulDB Data Team • 08/11/2026
The vulnerability in the Linux kernel's wilc1000 wireless driver represents a critical buffer overflow condition that arises from inadequate input validation during association response processing. This flaw exists within the wilc_parse_assoc_resp_info() function where the driver calculates trailing IE length without first verifying that the received buffer contains sufficient data to accommodate the fixed header structure. The specific issue occurs when buffer_len, which represents the reported length of an incoming association response frame, is used directly in arithmetic operations without proper bounds checking against the expected minimum size of 6 bytes required for the wilc_assoc_resp structure.
The technical implementation of this vulnerability demonstrates a classic integer underflow scenario that manifests through improper validation of received network frames. When a malformed association response contains fewer bytes than the expected 6-byte fixed header, the arithmetic operation ies_len = buffer_len - sizeof(*res) results in integer wraparound behavior. For instance, a four-byte response produces an unsigned 16-bit ies_len value of 65534, causing subsequent kmemdup() operations to attempt copying an enormous amount of memory beyond the actual valid data boundaries. This condition directly maps to CWE-125, which describes out-of-bounds read vulnerabilities resulting from improper input validation and arithmetic overflow scenarios.
The operational impact of this vulnerability extends beyond simple buffer overflows to encompass potential system instability and security risks within wireless network communications. An attacker could exploit this weakness by transmitting malformed association responses that trigger memory corruption during the parsing process, potentially leading to kernel crashes or arbitrary code execution in privileged contexts. The vulnerability affects the wilc1000 driver's ability to properly validate incoming wireless frames, creating opportunities for malicious actors to disrupt wireless connectivity or escalate privileges through kernel memory corruption. This type of vulnerability aligns with ATT&CK technique T1068, which covers local privilege escalation through kernel exploits and memory corruption attacks.
The remediation approach requires implementing strict input validation before any header access or length calculations occur. The fix must reject association response frames that are too short to contain the expected fixed header structure, ensuring that buffer_len is always validated against sizeof(struct wilc_assoc_resp) before performing any arithmetic operations. Additionally, the connection status must be explicitly set to failure when malformed responses are detected, preventing the caller from inadvertently treating invalid responses as successful associations. This correction addresses both the immediate memory safety issue and prevents logical errors in connection state management that could allow continued operation with corrupted network configurations. The implementation should follow established security practices for input validation and boundary checking as recommended by industry standards including CWE guidelines for buffer overflow prevention and secure coding practices for kernel-level network drivers.