Re: [PATCH] lsm: Fix the crash issue in xfrm_decode_session

[Feng Yang]

> After hooking the following BPF program:
> SEC("lsm/xfrm_decode_session")
> int BPF_PROG(lsm_hook_xfrm_decode_session, struct sk_buff *skb, u32 *secid, int ckall)
> {
>     return 1; // Any non-zero value

There is an error here. Any error value between -4095 and -1 will trigger this bug,
while other values in the range [-4095, 0] will be rejected by the validator.

> }