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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-10-29 19:59:40 +0200 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2010-10-29 19:59:40 +0200 |
| commit | d817d29d0b37290d90b3a9e2a61162f1dbf2be4f (patch) | |
| tree | 7414a1334cdac82a61340623a23109c3222f4a48 | |
| parent | 64e46749224aa658d8fc0d37ea83ab20b1d7955d (diff) | |
| download | op-kernel-dev-d817d29d0b37290d90b3a9e2a61162f1dbf2be4f.zip op-kernel-dev-d817d29d0b37290d90b3a9e2a61162f1dbf2be4f.tar.gz | |
netfilter: fix nf_conntrack_l4proto_register()
While doing __rcu annotations work on net/netfilter I found following
bug. On some arches, it is possible we publish a table while its content
is not yet committed to memory, and lockless reader can dereference wild
pointer.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
| -rw-r--r-- | net/netfilter/nf_conntrack_proto.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c index ed6d929..dc7bb74 100644 --- a/net/netfilter/nf_conntrack_proto.c +++ b/net/netfilter/nf_conntrack_proto.c @@ -292,6 +292,12 @@ int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto) for (i = 0; i < MAX_NF_CT_PROTO; i++) proto_array[i] = &nf_conntrack_l4proto_generic; + + /* Before making proto_array visible to lockless readers, + * we must make sure its content is committed to memory. + */ + smp_wmb(); + nf_ct_protos[l4proto->l3proto] = proto_array; } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != &nf_conntrack_l4proto_generic) { |
