On 05/16/2015, 08:50 PM, Pablo Neira Ayuso wrote: > From: Ian Wilson <iwilson@xxxxxxxxxxx> > > [ upstream commit 78146572b9cd20452da47951812f35b1ad4906be ] > > 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. > > Cc: <stable@xxxxxxxxxxxxxxx> # 3.10.x > Cc: <stable@xxxxxxxxxxxxxxx> # 3.12.x Applied only this one to 3.12 (others are not marked as such). Thanks. > Cc: <stable@xxxxxxxxxxxxxxx> # 3.14.x > Cc: <stable@xxxxxxxxxxxxxxx> # 3.18.x > Cc: <stable@xxxxxxxxxxxxxxx> # 3.19.x > Signed-off-by: Ian Wilson <iwilson@xxxxxxxxxxx> > Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> > --- > net/netfilter/nfnetlink_cthelper.c | 3 +++ > 1 file changed, 3 insertions(+) > > 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]); > > -- js suse labs -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
