Re: [PATCH bpf-next] uprobes: Harden uretprobe syscall trampoline check

[Kees Cook]

On Sun, Feb 09, 2025 at 11:05:15PM +0100, Jiri Olsa wrote:
> Jann reported [1] possible issue when trampoline_check_ip returns
> address near the bottom of the address space that is allowed to
> call into the syscall if uretprobes are not set up.
> 
> Though the mmap minimum address restrictions will typically prevent
> creating mappings there, let's make sure uretprobe syscall checks
> for that.
> 
> [1] https://lore.kernel.org/bpf/202502081235.5A6F352985@keescook/T/#m9d416df341b8fbc11737dacbcd29f0054413cbbf
> Cc: Kees Cook <kees@xxxxxxxxxx>
> Cc: Eyal Birger <eyal.birger@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Jann Horn <jannh@xxxxxxxxxx>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>

Thanks for this!

Reviewed-by: Kees Cook <kees@xxxxxxxxxx>

-- 
Kees Cook