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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7969C32750 for ; Tue, 13 Aug 2019 20:12:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 926252067D for ; Tue, 13 Aug 2019 20:12:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726708AbfHMUM0 (ORCPT ); Tue, 13 Aug 2019 16:12:26 -0400 Received: from Chamillionaire.breakpoint.cc ([193.142.43.52]:57620 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726231AbfHMUM0 (ORCPT ); Tue, 13 Aug 2019 16:12:26 -0400 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.89) (envelope-from ) id 1hxd9c-0004BF-3n; Tue, 13 Aug 2019 22:12:24 +0200 From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH nftables 1/3] src: fix jumps on bigendian arches Date: Tue, 13 Aug 2019 22:12:44 +0200 Message-Id: <20190813201246.5543-2-fw@strlen.de> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190813201246.5543-1-fw@strlen.de> References: <20190813201246.5543-1-fw@strlen.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org table bla { chain foo { } chain bar { jump foo } } } Fails to restore on big-endian platforms: jump.nft:5:2-9: Error: Could not process rule: No such file or directory jump foo nft passes a 0-length name to the kernel. This is because when we export the value (the string), we provide the size of the destination buffer. In earlier versions, the parser allocated the name with the same fixed size and all was fine. After the fix, the export places the name in the wrong location in the destination buffer. This makes tests/shell/testcases/chains/0001jumps_0 work on s390x. v2: convert one error check to a BUG(), it should not happen unless kernel abi is broken. Fixes: 142350f154c78 ("src: invalid read when importing chain name") Signed-off-by: Florian Westphal --- src/datatype.c | 27 ++++++++++++++++++--------- src/netlink.c | 16 +++++++++++++--- 2 files changed, 31 insertions(+), 12 deletions(-) diff --git a/src/datatype.c b/src/datatype.c index 28f726f4e84c..c5a013463eb9 100644 --- a/src/datatype.c +++ b/src/datatype.c @@ -244,10 +244,25 @@ const struct datatype invalid_type = { .print = invalid_type_print, }; -static void verdict_type_print(const struct expr *expr, struct output_ctx *octx) +static void verdict_jump_chain_print(const char *what, const struct expr *e, + struct output_ctx *octx) { char chain[NFT_CHAIN_MAXNAMELEN]; + unsigned int len; + + memset(chain, 0, sizeof(chain)); + len = e->len / BITS_PER_BYTE; + if (len >= sizeof(chain)) + BUG("verdict expression length %u is too large (%lu bits max)", + e->len, (unsigned long)sizeof(chain) * BITS_PER_BYTE); + + mpz_export_data(chain, e->value, BYTEORDER_HOST_ENDIAN, len); + nft_print(octx, "%s %s", what, chain); +} + +static void verdict_type_print(const struct expr *expr, struct output_ctx *octx) +{ switch (expr->verdict) { case NFT_CONTINUE: nft_print(octx, "continue"); @@ -257,10 +272,7 @@ static void verdict_type_print(const struct expr *expr, struct output_ctx *octx) break; case NFT_JUMP: if (expr->chain->etype == EXPR_VALUE) { - mpz_export_data(chain, expr->chain->value, - BYTEORDER_HOST_ENDIAN, - NFT_CHAIN_MAXNAMELEN); - nft_print(octx, "jump %s", chain); + verdict_jump_chain_print("jump", expr->chain, octx); } else { nft_print(octx, "jump "); expr_print(expr->chain, octx); @@ -268,10 +280,7 @@ static void verdict_type_print(const struct expr *expr, struct output_ctx *octx) break; case NFT_GOTO: if (expr->chain->etype == EXPR_VALUE) { - mpz_export_data(chain, expr->chain->value, - BYTEORDER_HOST_ENDIAN, - NFT_CHAIN_MAXNAMELEN); - nft_print(octx, "goto %s", chain); + verdict_jump_chain_print("goto", expr->chain, octx); } else { nft_print(octx, "goto "); expr_print(expr->chain, octx); diff --git a/src/netlink.c b/src/netlink.c index aeeb12eaca93..f8e1120447d9 100644 --- a/src/netlink.c +++ b/src/netlink.c @@ -222,17 +222,27 @@ static void netlink_gen_verdict(const struct expr *expr, struct nft_data_linearize *data) { char chain[NFT_CHAIN_MAXNAMELEN]; + unsigned int len; data->verdict = expr->verdict; switch (expr->verdict) { case NFT_JUMP: case NFT_GOTO: + len = expr->chain->len / BITS_PER_BYTE; + + if (!len) + BUG("chain length is 0"); + + if (len > sizeof(chain)) + BUG("chain is too large (%u, %u max)", + len, (unsigned int)sizeof(chain)); + + memset(chain, 0, sizeof(chain)); + mpz_export_data(chain, expr->chain->value, - BYTEORDER_HOST_ENDIAN, - NFT_CHAIN_MAXNAMELEN); + BYTEORDER_HOST_ENDIAN, len); snprintf(data->chain, NFT_CHAIN_MAXNAMELEN, "%s", chain); - data->chain[NFT_CHAIN_MAXNAMELEN-1] = '\0'; break; } } -- 2.21.0