5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yuqi Xu commit 5bfd4b0b40b79781d900cb2f7da0685070f53c67 upstream. 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. Fixes: 39404feee691 ("mac80211: FILS AEAD protection for station mode association frames") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: LLM Signed-off-by: Yuqi Xu Reviewed-by: Ren Wei Link: https://patch.msgid.link/325c048982d637a3af80d74ac5b36e9369b93f1e.1789751126.git.xuyuqiabc@gmail.com Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/fils_aead.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/net/mac80211/fils_aead.c +++ b/net/mac80211/fils_aead.c @@ -95,6 +95,14 @@ static int aes_siv_encrypt(const u8 *key if (res) return res; + /* With an empty plaintext there is no ciphertext to produce and + * the S2V result is the complete output. + */ + if (!plain_len) { + memcpy(out, v, AES_BLOCK_SIZE); + return 0; + } + /* Use a temporary buffer of the plaintext to handle need for * overwriting this during AES-CTR. */