From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A7DC17741 for ; Tue, 19 Dec 2023 11:14:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=breakpoint.cc Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1rFY3h-00031g-JP; Tue, 19 Dec 2023 12:14:45 +0100 From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH nft] intervals: BUG on prefix expressions without value Date: Tue, 19 Dec 2023 12:14:37 +0100 Message-ID: <20231219111440.12564-1-fw@strlen.de> X-Mailer: git-send-email 2.41.0 Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Its possible to end up with prefix expressions that have a symbolic expression, e.g.: table t { set s { type inet_service flags interval elements = { 0-1024, 8080-8082, 10000-40000 } elements = { 172.16.0.0/16 } } set s { type inet_service flags interval elements = { 0-1024, 8080-8082, 10000-40000 } } } Without this change, nft will crash. We end up in setelem_expr_to_range() with prefix "/16" for the symbolic expression "172.16.0.0". We than pass invalid mpz_t pointer into libgmp. This isn't the right fix (see next patch), but instead of blindly assuming that the attached expression has a gmp value die with at least some info. Its possible there are more ways than one to feed such "symbol-with-prefix" down into the interval code, so also add this assertion. Signed-off-by: Florian Westphal --- src/intervals.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/intervals.c b/src/intervals.c index e535fc34afda..5a88a8eb20bd 100644 --- a/src/intervals.c +++ b/src/intervals.c @@ -28,6 +28,9 @@ static void setelem_expr_to_range(struct expr *expr) case EXPR_RANGE: break; case EXPR_PREFIX: + if (expr->key->prefix->etype != EXPR_VALUE) + BUG("Prefix for unexpected type %d", expr->key->prefix->etype); + mpz_init(rop); mpz_bitmask(rop, expr->key->len - expr->key->prefix_len); if (expr_basetype(expr)->type == TYPE_STRING) -- 2.41.0