From 6a2a56fcb81cf2e5ef46d37001810b82a56a42a5 Mon Sep 17 00:00:00 2001 From: Jeremy Sowden Date: Mon, 6 Jan 2020 22:35:10 +0000 Subject: evaluate: fix expr_set_context call for shift binops. expr_evaluate_binop calls expr_set_context for shift expressions to set the context data-type to `integer`. This clobbers the byte-order of the context, resulting in unexpected conversions to NBO. For example: $ sudo nft flush ruleset $ sudo nft add table t $ sudo nft add chain t c '{ type filter hook output priority mangle; }' $ sudo nft add rule t c oif lo tcp dport ssh ct mark set '0x10 | 0xe' $ sudo nft add rule t c oif lo tcp dport ssh ct mark set '0xf << 1' $ sudo nft list table t table ip t { chain c { type filter hook output priority mangle; policy accept; oif "lo" tcp dport 22 ct mark set 0x0000001e oif "lo" tcp dport 22 ct mark set 0x1e000000 } } Replace it with a call to __expr_set_context and set the byteorder to that of the left operand since this is the value being shifted. Signed-off-by: Jeremy Sowden Signed-off-by: Pablo Neira Ayuso --- src/evaluate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/evaluate.c b/src/evaluate.c index 817b2322..34e4473e 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -1145,7 +1145,8 @@ static int expr_evaluate_binop(struct eval_ctx *ctx, struct expr **expr) left = op->left; if (op->op == OP_LSHIFT || op->op == OP_RSHIFT) - expr_set_context(&ctx->ectx, &integer_type, ctx->ectx.len); + __expr_set_context(&ctx->ectx, &integer_type, + left->byteorder, ctx->ectx.len, 0); if (expr_evaluate(ctx, &op->right) < 0) return -1; right = op->right; -- cgit v1.2.3