tls: rx: always allocate max possible aad size for decrypt

AAD size is either 5 or 13. Really no point complicating
the code for the 8B of difference. This will also let us
turn the chunked up buffer into a sane struct.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/tls.h b/include/net/tls.h
index 4fc16ca5f469a0fa8eca7164eb99d2fbaf77f475..9394c0459fe8722562e880b86651effe959eb08b 100644 (file)
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -66,6 +66,7 @@
 #define MAX_IV_SIZE                    16
 #define TLS_TAG_SIZE                   16
 #define TLS_MAX_REC_SEQ_SIZE           8
+#define TLS_MAX_AAD_SIZE               TLS_AAD_SPACE_SIZE
 
 /* For CCM mode, the full 16-bytes of IV is made of '4' fields of given sizes.
  *

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index f1777d67527fa1bf95e544f8a0a34bebbdb46843..377c0f60816732fc95c57378f8b7c929d814786c 100644 (file)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1450,7 +1450,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
 
        aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv);
        mem_size = aead_size + (nsg * sizeof(struct scatterlist));
-       mem_size = mem_size + prot->aad_size;
+       mem_size = mem_size + TLS_MAX_AAD_SIZE;
        mem_size = mem_size + MAX_IV_SIZE;
        mem_size = mem_size + prot->tail_size;
 
@@ -1467,7 +1467,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
        sgin = (struct scatterlist *)(mem + aead_size);
        sgout = sgin + n_sgin;
        aad = (u8 *)(sgout + n_sgout);
-       iv = aad + prot->aad_size;
+       iv = aad + TLS_MAX_AAD_SIZE;
        tail = iv + MAX_IV_SIZE;
 
        /* For CCM based ciphers, first byte of nonce+iv is a constant */
@@ -2474,13 +2474,6 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
                goto free_priv;
        }
 
-       /* Sanity-check the sizes for stack allocations. */
-       if (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE ||
-           rec_seq_size > TLS_MAX_REC_SEQ_SIZE || tag_size != TLS_TAG_SIZE) {
-               rc = -EINVAL;
-               goto free_priv;
-       }
-
        if (crypto_info->version == TLS_1_3_VERSION) {
                nonce_size = 0;
                prot->aad_size = TLS_HEADER_SIZE;
@@ -2490,6 +2483,14 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
                prot->tail_size = 0;
        }
 
+       /* Sanity-check the sizes for stack allocations. */
+       if (iv_size > MAX_IV_SIZE || nonce_size > MAX_IV_SIZE ||
+           rec_seq_size > TLS_MAX_REC_SEQ_SIZE || tag_size != TLS_TAG_SIZE ||
+           prot->aad_size > TLS_MAX_AAD_SIZE) {
+               rc = -EINVAL;
+               goto free_priv;
+       }
+
        prot->version = crypto_info->version;
        prot->cipher_type = crypto_info->cipher_type;
        prot->prepend_size = TLS_HEADER_SIZE + nonce_size;