From d344591e72e5ca96a2bf70a2df38961553185ce8 Mon Sep 17 00:00:00 2001 From: HsiuWen Yen Date: Fri, 21 Jun 2019 00:44:42 +0800 Subject: [PATCH] netfilter: fix crash in flow offload by adding netns support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit fcb41decf6c6 ("config: enable some useful features on !SMALL_FLASH devices") enabled netns, which in turn lead to the crash in the flow offload target. When the flow offloading framework intends to delete a flow from the hardware table, it is necessary to retrieve the namespace from nf_flowtable->ft_net. However, no one ever wrote the namespace into nf_flowtable->ft_net in advance. So the framework will mistakenly use a NULL namespace to execute dev_get_by_index_rcu(net, ifindex), leading to the kernel panic. Ref: FS#2321 Fixes: fcb41decf6c6 ("config: enable some useful features on !SMALL_FLASH devices") Tested-by: Simon Tretter Signed-off-by: HsiuWen Yen [merged patch into offload patch, fix for 4.19, SOB fix, commit subj/msg touches] Signed-off-by: Petr Štetiar --- .../hack-4.14/650-netfilter-add-xt_OFFLOAD-target.patch | 9 +++++++-- .../hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch | 7 ++++++- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/target/linux/generic/hack-4.14/650-netfilter-add-xt_OFFLOAD-target.patch b/target/linux/generic/hack-4.14/650-netfilter-add-xt_OFFLOAD-target.patch index b78ba1f53f..9692aa8a2b 100644 --- a/target/linux/generic/hack-4.14/650-netfilter-add-xt_OFFLOAD-target.patch +++ b/target/linux/generic/hack-4.14/650-netfilter-add-xt_OFFLOAD-target.patch @@ -98,7 +98,7 @@ Signed-off-by: Felix Fietkau obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o --- /dev/null +++ b/net/netfilter/xt_FLOWOFFLOAD.c -@@ -0,0 +1,403 @@ +@@ -0,0 +1,408 @@ +/* + * Copyright (C) 2018 Felix Fietkau + * @@ -342,12 +342,13 @@ Signed-off-by: Felix Fietkau +flowoffload_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct xt_flowoffload_target_info *info = par->targinfo; ++ const struct nf_conn_help *help; + enum ip_conntrack_info ctinfo; + enum ip_conntrack_dir dir; + struct nf_flow_route route; + struct flow_offload *flow; + struct nf_conn *ct; -+ const struct nf_conn_help *help; ++ struct net *net; + + if (xt_flowoffload_skip(skb)) + return XT_CONTINUE; @@ -396,6 +397,10 @@ Signed-off-by: Felix Fietkau + xt_flowoffload_check_device(xt_in(par)); + xt_flowoffload_check_device(xt_out(par)); + ++ net = read_pnet(&nf_flowtable.ft_net); ++ if (!net) ++ write_pnet(&nf_flowtable.ft_net, xt_net(par)); ++ + if (info->flags & XT_FLOWOFFLOAD_HW) + nf_flow_offload_hw_add(xt_net(par), flow, ct); + diff --git a/target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch b/target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch index 8ebea32a82..b207f9d084 100644 --- a/target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch +++ b/target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch @@ -98,7 +98,7 @@ Signed-off-by: Felix Fietkau obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o --- /dev/null +++ b/net/netfilter/xt_FLOWOFFLOAD.c -@@ -0,0 +1,366 @@ +@@ -0,0 +1,371 @@ +/* + * Copyright (C) 2018 Felix Fietkau + * @@ -344,6 +344,7 @@ Signed-off-by: Felix Fietkau + struct nf_flow_route route; + struct flow_offload *flow; + struct nf_conn *ct; ++ struct net *net; + + if (xt_flowoffload_skip(skb)) + return XT_CONTINUE; @@ -391,6 +392,10 @@ Signed-off-by: Felix Fietkau + xt_flowoffload_check_device(xt_in(par)); + xt_flowoffload_check_device(xt_out(par)); + ++ net = read_pnet(&nf_flowtable.ft_net); ++ if (!net) ++ write_pnet(&nf_flowtable.ft_net, xt_net(par)); ++ + if (info->flags & XT_FLOWOFFLOAD_HW) + nf_flow_offload_hw_add(xt_net(par), flow, ct); +