Re: [PATCH] kprobes: Limit max data_size of the kretprobe instances
From: Steven Rostedt
Date: Wed Dec 01 2021 - 11:19:39 EST
On Wed, 1 Dec 2021 23:45:50 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
> The kretprobe::data_size is unsigned (size_t) but it is
> used as 'data_size + sizeof(struct kretprobe_instance)'.
> Thus, it can be smaller than sizeof(struct kretprobe_instance)
> while allocating memory for the kretprobe_instance.
The above doesn't make sense.
data_size is unsigned but it is used as
'data_size + sizeof(struct kretprobe_instance)'.
What does that mean?
What can be smaller than sizeof(struct kretprobe_instance) and why does it
matter?
-- Steve
>
> To avoid this issue, introduce a max limitation of the
> kretprobe::data_size. 4KB per instance should be OK.
>