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| author | Ian Wilson <iwilson@brocade.com> | 2015-03-12 09:37:58 +0000 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2015-03-12 13:07:36 +0100 |
| commit | 78146572b9cd20452da47951812f35b1ad4906be (patch) | |
| tree | b824681ec5313d56424b617a44b1c60cace8d488 /net | |
| parent | 4363890079674db7b00cf1bb0e6fa430e846e86b (diff) | |
| download | op-kernel-dev-78146572b9cd20452da47951812f35b1ad4906be.zip op-kernel-dev-78146572b9cd20452da47951812f35b1ad4906be.tar.gz | |
netfilter: Zero the tuple in nfnl_cthelper_parse_tuple()
nfnl_cthelper_parse_tuple() is called from nfnl_cthelper_new(),
nfnl_cthelper_get() and nfnl_cthelper_del(). In each case they pass
a pointer to an nf_conntrack_tuple data structure local variable:
struct nf_conntrack_tuple tuple;
...
ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
The problem is that this local variable is not initialized, and
nfnl_cthelper_parse_tuple() only initializes two fields: src.l3num and
dst.protonum. This leaves all other fields with undefined values
based on whatever is on the stack:
tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM]));
tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
The symptom observed was that when the rpc and tns helpers were added
then traffic to port 1536 was being sent to user-space.
Signed-off-by: Ian Wilson <iwilson@brocade.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nfnetlink_cthelper.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c index a5599fc..54330fb 100644 --- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -77,6 +77,9 @@ nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple, if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM]) return -EINVAL; + /* Not all fields are initialized so first zero the tuple */ + memset(tuple, 0, sizeof(struct nf_conntrack_tuple)); + tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM])); tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]); |
