Re: [PATCH net v3] tipc: check minimum bearer MTU

[Ying Xue]

On 12/02/2016 04:33 PM, Michal Kubecek wrote:
> Qian Zhang (åè) reported a potential socket buffer overflow in
> tipc_msg_build() which is also known as CVE-2016-8632: due to
> insufficient checks, a buffer overflow can occur if MTU is too short for
> even tipc headers. As anyone can set device MTU in a user/net namespace,
> this issue can be abused by a regular user.
>
> As agreed in the discussion on Ben Hutchings' original patch, we should
> check the MTU at the moment a bearer is attached rather than for each
> processed packet. We also need to repeat the check when bearer MTU is
> adjusted to new device MTU. UDP case also needs a check to avoid
> overflow when calculating bearer MTU.
>
> Fixes: b97bf3fd8f6a ("[TIPC] Initial merge")
> Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
> Reported-by: Qian Zhang (åè) <zhangqian-c@xxxxxx>
> ---

Thanks, it looks nice to me.

Acked-by: Ying Xue <ying.xue@xxxxxxxxxxxxx>