Re: Crash when attaching uretprobes to processes running in Docker

From: Jiri Olsa
Date: Tue Jan 14 2025 - 09:57:26 EST


On Tue, Jan 14, 2025 at 03:33:13PM +0100, Oleg Nesterov wrote:
> On 01/14, Eyal Birger wrote:
> >
> > FWIW If I change the seccomp policy to SCMP_ACT_KILL this still fails.
>
> Ah... I don't know what SCMP_ACT_KILL is, but indeed, in general it is
> not safe to even try to call sys_uretprobe() if it is filtered.
>
> Say, __secure_computing(SECCOMP_MODE_STRICT)->__secure_computing_strict()
> does do_exit(SIGKILL) :/

ugh.. could we just 'disable' uretprobe trampoline when seccomp gets enabled?
overwrite first byte with int3.. and similarly check on seccomp when installing
uretprobe and switch to int3

jirka