CVE-2026-98698: wifi: mac80211: handle empty FILS association request payload
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: handle empty FILS association request payload
filsencryptassocreq() accepts a (Re)Association Request frame whose last element is the FILS Session element. cryptlen is then zero and aessivencrypt() is called with an empty plaintext.
kmemdup() returns ZEROSIZEPTR for a zero-length allocation, so the unconditional sginitone() puts an invalid page into the scatterlist. With CONFIGDEBUGSG this triggers a kernel BUG in sgsetbuf(); 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Update aes_siv_encrypt() to handle empty plaintext before the CTR step, so no encryption is attempted and sg_init_one() is not called with the invalid zero-length allocation page.