On 04/16/2018 11:29 PM, Eric Dumazet wrote:
> syzbot reported a crash in __tipc_nl_net_set() caused by NULL dereference.
>
> We need to check that both TIPC_NLA_NET_NODEID and TIPC_NLA_NET_NODEID_W1
> are present.
>
> We also need to make sure userland provided u64 attributes.
>
> Fixes: d50ccc2d3909 ("tipc: add 128-bit node identifier")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Cc: Jon Maloy <jon.ma...@ericsson.com>
> Cc: Ying Xue <ying....@windriver.com>
> Reported-by: syzbot <syzkal...@googlegroups.com>
Acked-by: Ying Xue <ying....@windriver.com>
> ---
> net/tipc/net.c | 2 ++
> net/tipc/netlink.c | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/net/tipc/net.c b/net/tipc/net.c
> index
> 856f9e97ea293210bea1d2003d2092482732ace9..4fbaa0464405370601cb2fd1dd3b03733836d342
> 100644
> --- a/net/tipc/net.c
> +++ b/net/tipc/net.c
> @@ -252,6 +252,8 @@ int __tipc_nl_net_set(struct sk_buff *skb, struct
> genl_info *info)
> u64 *w0 = (u64 *)&node_id[0];
> u64 *w1 = (u64 *)&node_id[8];
>
> + if (!attrs[TIPC_NLA_NET_NODEID_W1])
> + return -EINVAL;
> *w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]);
> *w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]);
> tipc_net_init(net, node_id, 0);
> diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
> index
> d4e0bbeee72793a060befaf8a9d0239731c0d48c..6ff2254088f647d4f7410c3335ccdae2e68ec522
> 100644
> --- a/net/tipc/netlink.c
> +++ b/net/tipc/netlink.c
> @@ -81,6 +81,8 @@ const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX
> + 1] = {
> [TIPC_NLA_NET_UNSPEC] = { .type = NLA_UNSPEC },
> [TIPC_NLA_NET_ID] = { .type = NLA_U32 },
> [TIPC_NLA_NET_ADDR] = { .type = NLA_U32 },
> + [TIPC_NLA_NET_NODEID] = { .type = NLA_U64 },
> + [TIPC_NLA_NET_NODEID_W1] = { .type = NLA_U64 },
> };
>
> const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
>
