From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A7F4EB64D7 for ; Tue, 20 Jun 2023 16:02:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232057AbjFTQCo (ORCPT ); Tue, 20 Jun 2023 12:02:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229896AbjFTQCn (ORCPT ); Tue, 20 Jun 2023 12:02:43 -0400 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6C66D188 for ; Tue, 20 Jun 2023 09:02:41 -0700 (PDT) Date: Tue, 20 Jun 2023 18:02:36 +0200 From: Pablo Neira Ayuso To: Florian Westphal Cc: netfilter-devel@vger.kernel.org Subject: Re: [PATCH nft 4/6] parser: reject zero-length interface names Message-ID: References: <20230619204306.11785-1-fw@strlen.de> <20230619204306.11785-5-fw@strlen.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230619204306.11785-5-fw@strlen.de> Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Mon, Jun 19, 2023 at 10:43:04PM +0200, Florian Westphal wrote: > device "" results in an assertion during evaluation. > Before: > nft: expression.c:426: constant_expr_alloc: Assertion `(((len) + (8) - 1) / (8)) > 0' failed. > After: > zero_length_devicename_assert:3:42-49: Error: you cannot set an empty interface name > type filter hook ingress device""lo" priority -1 > ^^^^^^^^ > Signed-off-by: Florian Westphal > --- > src/parser_bison.y | 36 ++++++++++++++++--- > .../nft-f/zero_length_devicename_assert | 5 +++ > 2 files changed, 36 insertions(+), 5 deletions(-) > create mode 100644 tests/shell/testcases/bogons/nft-f/zero_length_devicename_assert > > diff --git a/src/parser_bison.y b/src/parser_bison.y > index f5f6bf04d064..d5a2f85387cb 100644 > --- a/src/parser_bison.y > +++ b/src/parser_bison.y > @@ -144,6 +144,33 @@ static bool already_set(const void *attr, const struct location *loc, > return true; > } > > +static struct expr* ifname_expr_alloc(const struct location *location, Nitpick: static struct expr *ifname_expr_alloc(const struct location *location, ^ > + struct list_head *queue, > + const char *name) > +{ > + unsigned int length = strlen(name); > + struct expr *expr; > + > + if (length == 0) { > + xfree(name); > + erec_queue(error(location, "empty interface name"), queue); > + return NULL; > + } > + > + if (length > 16) { IFNAMSIZ instead of 16? > + xfree(name); > + erec_queue(error(location, "interface name too long"), queue); > + return NULL; > + } > + > + expr = constant_expr_alloc(location, &ifname_type, BYTEORDER_HOST_ENDIAN, > + length * BITS_PER_BYTE, name); > + > + xfree(name); > + > + return expr; > +} > + > #define YYLLOC_DEFAULT(Current, Rhs, N) location_update(&Current, Rhs, N) > > #define symbol_value(loc, str) \ > @@ -2664,12 +2691,11 @@ int_num : NUM { $$ = $1; } > > dev_spec : DEVICE string > { > - struct expr *expr; > + struct expr *expr = ifname_expr_alloc(&@$, state->msgs, $2); > + > + if (!expr) > + YYERROR; > > - expr = constant_expr_alloc(&@$, &string_type, > - BYTEORDER_HOST_ENDIAN, > - strlen($2) * BITS_PER_BYTE, $2); > - xfree($2); > $$ = compound_expr_alloc(&@$, EXPR_LIST); > compound_expr_add($$, expr); > > diff --git a/tests/shell/testcases/bogons/nft-f/zero_length_devicename_assert b/tests/shell/testcases/bogons/nft-f/zero_length_devicename_assert > new file mode 100644 > index 000000000000..84f330730fce > --- /dev/null > +++ b/tests/shell/testcases/bogons/nft-f/zero_length_devicename_assert > @@ -0,0 +1,5 @@ > +table ip x { > + chain Main_Ingress1 { > + type filter hook ingress device""lo" priority -1 > + } > +} > -- > 2.39.3 >