Re: [PATCH V2] net/ieee802154: fix uninit value bug in dgram_sendmsg

Hi,

On Tue, Aug 30, 2022 at 3:03 AM Haimin Zhang [off-list ref] wrote:

There is uninit value bug in dgram_sendmsg function in
net/ieee802154/socket.c when the length of valid data pointed by the
msg->msg_name isn't verified.

We should check the msg_namelen is not less than struct
sockaddr_ieee802154 when addr_type is SHORT before calling
ieee802154_addr_from_sa. So we define IEEE802154_MIN_NAMELEN.
And in function ieee802154_addr_from_sa, when
addr_type is LONG, we check msg_namelen is not less than
sizeof(struct sockaddr_ieee802154). Meanwhile we check in the
beginning of function dgram_sendmsg.

There exists also an IEEE802154_ADDR_NONE addr_type.

We need to first check that space is there to evaluate the addr_type.

If it's NONE, ignore hwaddr or short address. If it's SHORT or hwaddr
check if they have space for it, if it's something completely
different return -EINVAL.

There are still missing bits and I would recommend introducing a
helper function to do this "kind" of more complex check. This patch
spreads different checks around by checking on IEEE802154_MIN_NAMELEN
(which isn't correct, because NONE) and then requires another check by
calling ieee802154_addr_from_sa() and checking the return code.

- Alex