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96 lines
3.2 KiB
96 lines
3.2 KiB
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7 years ago
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From: Felix Fietkau <nbd@nbd.name>
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Date: Wed, 7 Feb 2018 09:23:25 +0100
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Subject: [PATCH] netfilter: nf_flow_offload: fix use-after-free and a resource
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leak
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flow_offload_del frees the flow, so all associated resource must be
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freed before.
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Since the ct entry in struct flow_offload_entry was allocated by
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flow_offload_alloc, it should be freed by flow_offload_free to take care
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of the error handling path when flow_offload_add fails.
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While at it, make flow_offload_del static, since it should never be
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called directly, only from the gc step
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Signed-off-by: Felix Fietkau <nbd@nbd.name>
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---
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--- a/include/net/netfilter/nf_flow_table.h
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+++ b/include/net/netfilter/nf_flow_table.h
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@@ -90,7 +90,6 @@ struct flow_offload *flow_offload_alloc(
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void flow_offload_free(struct flow_offload *flow);
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int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow);
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-void flow_offload_del(struct nf_flowtable *flow_table, struct flow_offload *flow);
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struct flow_offload_tuple_rhash *flow_offload_lookup(struct nf_flowtable *flow_table,
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struct flow_offload_tuple *tuple);
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int nf_flow_table_iterate(struct nf_flowtable *flow_table,
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--- a/net/netfilter/nf_flow_table.c
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+++ b/net/netfilter/nf_flow_table.c
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@@ -125,7 +125,9 @@ void flow_offload_free(struct flow_offlo
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dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache);
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dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache);
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e = container_of(flow, struct flow_offload_entry, flow);
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- kfree(e);
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+ nf_ct_delete(e->ct, 0, 0);
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+ nf_ct_put(e->ct);
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+ kfree_rcu(e, rcu_head);
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}
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EXPORT_SYMBOL_GPL(flow_offload_free);
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@@ -149,11 +151,9 @@ int flow_offload_add(struct nf_flowtable
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}
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EXPORT_SYMBOL_GPL(flow_offload_add);
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-void flow_offload_del(struct nf_flowtable *flow_table,
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- struct flow_offload *flow)
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+static void flow_offload_del(struct nf_flowtable *flow_table,
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+ struct flow_offload *flow)
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{
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- struct flow_offload_entry *e;
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-
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rhashtable_remove_fast(&flow_table->rhashtable,
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&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
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*flow_table->type->params);
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@@ -161,10 +161,8 @@ void flow_offload_del(struct nf_flowtabl
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&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
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*flow_table->type->params);
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- e = container_of(flow, struct flow_offload_entry, flow);
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- kfree_rcu(e, rcu_head);
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+ flow_offload_free(flow);
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}
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-EXPORT_SYMBOL_GPL(flow_offload_del);
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struct flow_offload_tuple_rhash *
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flow_offload_lookup(struct nf_flowtable *flow_table,
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@@ -175,15 +173,6 @@ flow_offload_lookup(struct nf_flowtable
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}
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EXPORT_SYMBOL_GPL(flow_offload_lookup);
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-static void nf_flow_release_ct(const struct flow_offload *flow)
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-{
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- struct flow_offload_entry *e;
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-
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- e = container_of(flow, struct flow_offload_entry, flow);
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- nf_ct_delete(e->ct, 0, 0);
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- nf_ct_put(e->ct);
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-}
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-
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int nf_flow_table_iterate(struct nf_flowtable *flow_table,
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void (*iter)(struct flow_offload *flow, void *data),
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void *data)
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@@ -259,10 +248,8 @@ static int nf_flow_offload_gc_step(struc
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flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
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if (nf_flow_has_expired(flow) ||
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- nf_flow_is_dying(flow)) {
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+ nf_flow_is_dying(flow))
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flow_offload_del(flow_table, flow);
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- nf_flow_release_ct(flow);
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- }
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}
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out:
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rhashtable_walk_stop(&hti);
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