diff --git a/net/mac80211/fils_aead.c b/net/mac80211/fils_aead.c
index 293590976489..9c4f00d61981 100644
--- a/net/mac80211/fils_aead.c
+++ b/net/mac80211/fils_aead.c
@@ -89,6 +89,14 @@ static int aes_siv_encrypt(const u8 *key, size_t key_len,
 	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.
 	 */