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 9740EC19F2B for ; Mon, 1 Aug 2022 17:16:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233704AbiHARQG (ORCPT ); Mon, 1 Aug 2022 13:16:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232994AbiHARPu (ORCPT ); Mon, 1 Aug 2022 13:15:50 -0400 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2792640E for ; Mon, 1 Aug 2022 10:15:48 -0700 (PDT) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1oIZ19-0001hW-7j; Mon, 01 Aug 2022 19:15:47 +0200 From: Florian Westphal To: Cc: Florian Westphal , Hangbin Liu Subject: [PATCH nf 1/2] netfilter: nf_tables: fix crash when nf_trace is enabled Date: Mon, 1 Aug 2022 19:15:35 +0200 Message-Id: <20220801171536.21372-2-fw@strlen.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220801171536.21372-1-fw@strlen.de> References: <20220801171536.21372-1-fw@strlen.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org nft_traceinfo is not initialized in info->trace is 0, so unconditional access to info->pkt (or any other field except ->trace) is illegal. Pass nft_pktinfo directly to avoid this. Fixes: e34b9ed96ce3 ("netfilter: nf_tables: avoid skb access on nf_stolen") Reported-by: Hangbin Liu Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_core.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c index 3ddce24ac76d..cee3e4e905ec 100644 --- a/net/netfilter/nf_tables_core.c +++ b/net/netfilter/nf_tables_core.c @@ -34,25 +34,23 @@ static noinline void __nft_trace_packet(struct nft_traceinfo *info, nft_trace_notify(info); } -static inline void nft_trace_packet(struct nft_traceinfo *info, +static inline void nft_trace_packet(const struct nft_pktinfo *pkt, + struct nft_traceinfo *info, const struct nft_chain *chain, const struct nft_rule_dp *rule, enum nft_trace_types type) { if (static_branch_unlikely(&nft_trace_enabled)) { - const struct nft_pktinfo *pkt = info->pkt; - info->nf_trace = pkt->skb->nf_trace; info->rule = rule; __nft_trace_packet(info, chain, type); } } -static inline void nft_trace_copy_nftrace(struct nft_traceinfo *info) +static inline void nft_trace_copy_nftrace(const struct nft_pktinfo *pkt, + struct nft_traceinfo *info) { if (static_branch_unlikely(&nft_trace_enabled)) { - const struct nft_pktinfo *pkt = info->pkt; - if (info->trace) info->nf_trace = pkt->skb->nf_trace; } @@ -96,7 +94,6 @@ static noinline void __nft_trace_verdict(struct nft_traceinfo *info, const struct nft_chain *chain, const struct nft_regs *regs) { - const struct nft_pktinfo *pkt = info->pkt; enum nft_trace_types type; switch (regs->verdict.code) { @@ -110,7 +107,9 @@ static noinline void __nft_trace_verdict(struct nft_traceinfo *info, break; default: type = NFT_TRACETYPE_RULE; - info->nf_trace = pkt->skb->nf_trace; + + if (info->trace) + info->nf_trace = info->pkt->skb->nf_trace; break; } @@ -271,10 +270,10 @@ nft_do_chain(struct nft_pktinfo *pkt, void *priv) switch (regs.verdict.code) { case NFT_BREAK: regs.verdict.code = NFT_CONTINUE; - nft_trace_copy_nftrace(&info); + nft_trace_copy_nftrace(pkt, &info); continue; case NFT_CONTINUE: - nft_trace_packet(&info, chain, rule, + nft_trace_packet(pkt, &info, chain, rule, NFT_TRACETYPE_RULE); continue; } @@ -318,7 +317,7 @@ nft_do_chain(struct nft_pktinfo *pkt, void *priv) goto next_rule; } - nft_trace_packet(&info, basechain, NULL, NFT_TRACETYPE_POLICY); + nft_trace_packet(pkt, &info, basechain, NULL, NFT_TRACETYPE_POLICY); if (static_branch_unlikely(&nft_counters_enabled)) nft_update_chain_stats(basechain, pkt); -- 2.35.1