evaluate: reject unsupported expressions in payload statement for bitfields

commit de447e248cce3ca3fd7040c386ac798c35721415 upstream.

The payload statement evaluation pretends that it can handle any
expression for bitfields, but the existing evaluation code only knows
how to handle value expression.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/evaluate.c b/src/evaluate.c
index de5ada83d5f68b2ab98ae7563f5984b0535efebf..ae5b07bab10ac07818f5ad66b0f4c99bdd8e824e 100644 (file)
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -3202,7 +3202,8 @@ static int stmt_evaluate_payload(struct eval_ctx *ctx, struct stmt *stmt)
                        mpz_lshift_ui(stmt->payload.val->value, shift_imm);
                break;
        default:
-               break;
+               return expr_error(ctx->msgs, stmt->payload.val,
+                                 "payload statement for this expression is not supported");
        }
 
        masklen = payload_byte_size * BITS_PER_BYTE;