From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Thu, 23 Mar 2023 11:52:39 +0000 (+0100)
Subject: evaluate: honor statement length in integer evaluation
X-Git-Tag: v1.0.6.1~187
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7f994db65db8969644133def6daac9c10bf5274f;p=thirdparty%2Fnftables.git

evaluate: honor statement length in integer evaluation

commit 3c64ea7995cbbc4f1d9d7707f907667325eb62b9 upstream.

Otherwise, bogus error is reported:

 # nft --debug=netlink add rule ip x y 'ct mark set ip dscp & 0x0f << 1 | 0xff000000'
 Error: Value 4278190080 exceeds valid range 0-63
 add rule ip x y ct mark set ip dscp & 0x0f << 1 | 0xff000000
                                                   ^^^^^^^^^^

Use the statement length as the maximum value in the mark statement
expression.

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

diff --git a/src/evaluate.c b/src/evaluate.c
index 80023834..8a7f95f3 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -423,6 +423,7 @@ static int expr_evaluate_integer(struct eval_ctx *ctx, struct expr **exprp)
 {
 	struct expr *expr = *exprp;
 	char *valstr, *rangestr;
+	uint32_t masklen;
 	mpz_t mask;
 
 	if (ctx->ectx.maxval > 0 &&
@@ -435,7 +436,12 @@ static int expr_evaluate_integer(struct eval_ctx *ctx, struct expr **exprp)
 		return -1;
 	}
 
-	mpz_init_bitmask(mask, ctx->ectx.len);
+	if (ctx->stmt_len > ctx->ectx.len)
+		masklen = ctx->stmt_len;
+	else
+		masklen = ctx->ectx.len;
+
+	mpz_init_bitmask(mask, masklen);
 	if (mpz_cmp(expr->value, mask) > 0) {
 		valstr = mpz_get_str(NULL, 10, expr->value);
 		rangestr = mpz_get_str(NULL, 10, mask);
@@ -448,7 +454,7 @@ static int expr_evaluate_integer(struct eval_ctx *ctx, struct expr **exprp)
 		return -1;
 	}
 	expr->byteorder = ctx->ectx.byteorder;
-	expr->len = ctx->ectx.len;
+	expr->len = masklen;
 	mpz_clear(mask);
 	return 0;
 }