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 9AA36C433EF for ; Fri, 3 Jun 2022 13:25:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233081AbiFCNZ1 (ORCPT ); Fri, 3 Jun 2022 09:25:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229922AbiFCNZ1 (ORCPT ); Fri, 3 Jun 2022 09:25:27 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39B84369C1 for ; Fri, 3 Jun 2022 06:25:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A9C91B822CE for ; Fri, 3 Jun 2022 13:25:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02533C385B8; Fri, 3 Jun 2022 13:25:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654262723; bh=copcsTzcke1ZSNLKBwzgM1xBFDQRelmUs6r1DhFuC80=; h=Subject:To:Cc:From:Date:From; b=h6VOFjobIq6SGM7JYz++LwLFRwDv5pawPXGLFWzz2P/qlQKpThLx91TOn3+e4viMg AjvV0Jn7YYxhLuRNwFhD7cmlfzwD9DfnFWxdCyqCpAzLHxDziU9IhwU7fiw5eCXUaX 44Nb45aQGCjAc5Vy6ezNx8tTMg767xTFMLUNOUBw= Subject: FAILED: patch "[PATCH] netfilter: nf_tables: disallow non-stateful expression in" failed to apply to 4.19-stable tree To: pablo@netfilter.org, edg-e@nccgroup.com Cc: From: Date: Fri, 03 Jun 2022 15:25:12 +0200 Message-ID: <16542627121689@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 520778042ccca019f3ffa136dd0ca565c486cedd Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 25 May 2022 10:36:38 +0200 Subject: [PATCH] netfilter: nf_tables: disallow non-stateful expression in sets earlier Since 3e135cd499bf ("netfilter: nft_dynset: dynamic stateful expression instantiation"), it is possible to attach stateful expressions to set elements. cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase") introduces conditional destruction on the object to accomodate transaction semantics. nft_expr_init() calls expr->ops->init() first, then check for NFT_STATEFUL_EXPR, this stills allows to initialize a non-stateful lookup expressions which points to a set, which might lead to UAF since the set is not properly detached from the set->binding for this case. Anyway, this combination is non-sense from nf_tables perspective. This patch fixes this problem by checking for NFT_STATEFUL_EXPR before expr->ops->init() is called. The reporter provides a KASAN splat and a poc reproducer (similar to those autogenerated by syzbot to report use-after-free errors). It is unknown to me if they are using syzbot or if they use similar automated tool to locate the bug that they are reporting. For the record, this is the KASAN splat. [ 85.431824] ================================================================== [ 85.432901] BUG: KASAN: use-after-free in nf_tables_bind_set+0x81b/0xa20 [ 85.433825] Write of size 8 at addr ffff8880286f0e98 by task poc/776 [ 85.434756] [ 85.434999] CPU: 1 PID: 776 Comm: poc Tainted: G W 5.18.0+ #2 [ 85.436023] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Fixes: 0b2d8a7b638b ("netfilter: nf_tables: add helper functions for expression handling") Reported-and-tested-by: Aaron Adams Signed-off-by: Pablo Neira Ayuso diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 12fc9cda4a2c..f296dfe86b62 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2873,27 +2873,31 @@ static struct nft_expr *nft_expr_init(const struct nft_ctx *ctx, err = nf_tables_expr_parse(ctx, nla, &expr_info); if (err < 0) - goto err1; + goto err_expr_parse; + + err = -EOPNOTSUPP; + if (!(expr_info.ops->type->flags & NFT_EXPR_STATEFUL)) + goto err_expr_stateful; err = -ENOMEM; expr = kzalloc(expr_info.ops->size, GFP_KERNEL_ACCOUNT); if (expr == NULL) - goto err2; + goto err_expr_stateful; err = nf_tables_newexpr(ctx, &expr_info, expr); if (err < 0) - goto err3; + goto err_expr_new; return expr; -err3: +err_expr_new: kfree(expr); -err2: +err_expr_stateful: owner = expr_info.ops->type->owner; if (expr_info.ops->type->release_ops) expr_info.ops->type->release_ops(expr_info.ops); module_put(owner); -err1: +err_expr_parse: return ERR_PTR(err); } @@ -5413,9 +5417,6 @@ struct nft_expr *nft_set_elem_expr_alloc(const struct nft_ctx *ctx, return expr; err = -EOPNOTSUPP; - if (!(expr->ops->type->flags & NFT_EXPR_STATEFUL)) - goto err_set_elem_expr; - if (expr->ops->type->flags & NFT_EXPR_GC) { if (set->flags & NFT_SET_TIMEOUT) goto err_set_elem_expr;