Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-10-18T00:00:00 kernel: wifi: mac80211: handle empty FILS association request payload 5.3 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CWE-617

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: handle empty FILS association request payload fils_encrypt_assoc_req() accepts a (Re)Association Request frame whose last element is the FILS Session element. crypt_len is then zero and aes_siv_encrypt() is called with an empty plaintext. kmemdup() returns ZERO_SIZE_PTR for a zero-length allocation, so the unconditional sg_init_one() puts an invalid page into the scatterlist. With CONFIG_DEBUG_SG this triggers a kernel BUG in sg_set_buf(); without the debug check the bogus page is handed to the crypto backend. AES-SIV is defined for empty plaintext and the S2V result is then the complete output, so handle this case before the CTR step, which has nothing to encrypt.

A flaw was found in the Linux kernel's mac80211 wireless subsystem. When handling a Fast Initial Link Setup (FILS) association request frame with an empty payload, the system fails to validate zero-length plaintext before cryptographic processing. This issue causes an invalid memory reference to be passed to the encryption backend, which can trigger a kernel crash. An adjacent attacker within Wi-Fi range could exploit this vulnerability to cause a Denial of Service (DoS).

This vulnerability is evaluated with a Moderate severity rating because successful exploitation is constrained to adjacent wireless proximity and requires an active Wi-Fi interface configured to process FILS-based associations. Standard Red Hat Enterprise Linux deployments and container host platforms typically run on server hardware without physical Wi-Fi adapters or wireless access point services enabled. Consequently, default installations face minimal exposure unless explicitly configured with supported wireless hardware. Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Fix deferred kernel Red Hat Enterprise Linux 8 Fix deferred kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt Red Hat OpenShift Container Platform 4 Fix deferred openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 4 Fix deferred openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 Fix deferred openshift/ose-rhel-coreos-9 https://www.cve.org/CVERecord?id=CVE-2026-98698 https://nvd.nist.gov/vuln/detail/CVE-2026-98698 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98698.mbox