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, URIBL_BLOCKED,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 921E2C433FF for ; Fri, 9 Aug 2019 10:41:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D7302086A for ; Fri, 9 Aug 2019 10:41:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405999AbfHIKll (ORCPT ); Fri, 9 Aug 2019 06:41:41 -0400 Received: from correo.us.es ([193.147.175.20]:35426 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726196AbfHIKll (ORCPT ); Fri, 9 Aug 2019 06:41:41 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id A8B79C3282 for ; Fri, 9 Aug 2019 12:41:38 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 94046DA704 for ; Fri, 9 Aug 2019 12:41:38 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 89A58DA72F; Fri, 9 Aug 2019 12:41:38 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 53AE3DA704 for ; Fri, 9 Aug 2019 12:41:36 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Fri, 09 Aug 2019 12:41:36 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from salvia.here (149.103.108.93.rev.vodafone.pt [93.108.103.149]) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPA id C78B04265A2F for ; Fri, 9 Aug 2019 12:41:35 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nf] netfilter: nf_tables: user-after-free in failing rule with bound set Date: Fri, 9 Aug 2019 12:41:18 +0200 Message-Id: <20190809104118.2415-1-pablo@netfilter.org> X-Mailer: git-send-email 2.11.0 X-Virus-Scanned: ClamAV using ClamSMTP Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org If a rule that has already a bound anonymous set fails to be added, the preparation phase releases the rule and the bound set. However, the transaction object from the abort path still has a reference to the set object that is stale, leading to a use-after-free when checking for the set->bound field. Add a new field to the transaction that specifies if the set is bound, so the abort path can skip releasing it since the rule command owns it and it takes care of releasing it. After this update, the set->bound field is removed. [ 24.649883] Unable to handle kernel paging request at virtual address 0000000000040434 [ 24.657858] Mem abort info: [ 24.660686] ESR = 0x96000004 [ 24.663769] Exception class = DABT (current EL), IL = 32 bits [ 24.669725] SET = 0, FnV = 0 [ 24.672804] EA = 0, S1PTW = 0 [ 24.675975] Data abort info: [ 24.678880] ISV = 0, ISS = 0x00000004 [ 24.682743] CM = 0, WnR = 0 [ 24.685723] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000428952000 [ 24.692207] [0000000000040434] pgd=0000000000000000 [ 24.697119] Internal error: Oops: 96000004 [#1] SMP [...] [ 24.889414] Call trace: [ 24.891870] __nf_tables_abort+0x3f0/0x7a0 [ 24.895984] nf_tables_abort+0x20/0x40 [ 24.899750] nfnetlink_rcv_batch+0x17c/0x588 [ 24.904037] nfnetlink_rcv+0x13c/0x190 [ 24.907803] netlink_unicast+0x18c/0x208 [ 24.911742] netlink_sendmsg+0x1b0/0x350 [ 24.915682] sock_sendmsg+0x4c/0x68 [ 24.919185] ___sys_sendmsg+0x288/0x2c8 [ 24.923037] __sys_sendmsg+0x7c/0xd0 [ 24.926628] __arm64_sys_sendmsg+0x2c/0x38 [ 24.930744] el0_svc_common.constprop.0+0x94/0x158 [ 24.935556] el0_svc_handler+0x34/0x90 [ 24.939322] el0_svc+0x8/0xc [ 24.942216] Code: 37280300 f9404023 91014262 aa1703e0 (f9401863) [ 24.948336] ---[ end trace cebbb9dcbed3b56f ]--- Fixes: f6ac85858976 ("netfilter: nf_tables: unbind set in rule from commit path") Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 9 +++++++-- net/netfilter/nf_tables_api.c | 15 ++++++++++----- 2 files changed, 17 insertions(+), 7 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 9b624566b82d..475d6f28ca67 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -421,8 +421,7 @@ struct nft_set { unsigned char *udata; /* runtime data below here */ const struct nft_set_ops *ops ____cacheline_aligned; - u16 flags:13, - bound:1, + u16 flags:14, genmask:2; u8 klen; u8 dlen; @@ -1348,12 +1347,15 @@ struct nft_trans_rule { struct nft_trans_set { struct nft_set *set; u32 set_id; + bool bound; }; #define nft_trans_set(trans) \ (((struct nft_trans_set *)trans->data)->set) #define nft_trans_set_id(trans) \ (((struct nft_trans_set *)trans->data)->set_id) +#define nft_trans_set_bound(trans) \ + (((struct nft_trans_set *)trans->data)->bound) struct nft_trans_chain { bool update; @@ -1384,12 +1386,15 @@ struct nft_trans_table { struct nft_trans_elem { struct nft_set *set; struct nft_set_elem elem; + bool bound; }; #define nft_trans_elem_set(trans) \ (((struct nft_trans_elem *)trans->data)->set) #define nft_trans_elem(trans) \ (((struct nft_trans_elem *)trans->data)->elem) +#define nft_trans_elem_set_bound(trans) \ + (((struct nft_trans_elem *)trans->data)->bound) struct nft_trans_obj { struct nft_object *obj; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 605a7cfe7ca7..88abbddf8967 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -138,9 +138,14 @@ static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set) return; list_for_each_entry_reverse(trans, &net->nft.commit_list, list) { - if (trans->msg_type == NFT_MSG_NEWSET && - nft_trans_set(trans) == set) { - set->bound = true; + switch (trans->msg_type) { + case NFT_MSG_NEWSET: + if (nft_trans_set(trans) == set) + nft_trans_set_bound(trans) = true; + break; + case NFT_MSG_NEWSETELEM: + if (nft_trans_elem_set(trans) == set) + nft_trans_elem_set_bound(trans) = true; break; } } @@ -6906,7 +6911,7 @@ static int __nf_tables_abort(struct net *net) break; case NFT_MSG_NEWSET: trans->ctx.table->use--; - if (nft_trans_set(trans)->bound) { + if (nft_trans_set_bound(trans)) { nft_trans_destroy(trans); break; } @@ -6918,7 +6923,7 @@ static int __nf_tables_abort(struct net *net) nft_trans_destroy(trans); break; case NFT_MSG_NEWSETELEM: - if (nft_trans_elem_set(trans)->bound) { + if (nft_trans_elem_set_bound(trans)) { nft_trans_destroy(trans); break; } -- 2.11.0