Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 05/22] netfilter: Zero the tuple in nfnl_cthelper_parse_tuple() | Date | Wed, 1 Jul 2015 11:40:10 -0700 |
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3.10-stable review patch. If anyone has any objections, please let me know.
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From: Ian Wilson <iwilson@brocade.com>
commit 78146572b9cd20452da47951812f35b1ad4906be upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/netfilter/nfnetlink_cthelper.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -74,6 +74,9 @@ nfnl_cthelper_parse_tuple(struct nf_conn 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]);
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