Em Thu, Nov 01, 2018 at 12:10:39PM -0700, David Miller escreveu:
> From: Arnaldo Carvalho de Melo <[email protected]>
> Date: Thu, 1 Nov 2018 15:52:17 -0300
>
> > 50 unsigned int filename_arg = 6;
> ...
> > --- /wb/augmented_raw_syscalls.c.old 2018-11-01 15:43:55.000394234
> > -0300
> > +++ /wb/augmented_raw_syscalls.c 2018-11-01 15:44:15.102367838 -0300
> > @@ -67,7 +67,7 @@
> > augmented_args.filename.reserved = 0;
> > augmented_args.filename.size =
> > probe_read_str(&augmented_args.filename.value,
> >
> > sizeof(augmented_args.filename.value),
> > - (const void
> > *)args->args[0]);
> > + (const void
> > *)args->args[filename_arg]);
>
> args[] is sized to '6', therefore the last valid index is '5', yet you're
> using '6' here which
> is one entry past the end of the declared array.
Nope... this is inside an if:
if (filename_arg <= 5) {
augmented_args.filename.reserved = 0;
augmented_args.filename.size =
probe_read_str(&augmented_args.filename.value,
sizeof(augmented_args.filename.value),
(const void
*)args->args[filename_arg]);
if (augmented_args.filename.size <
sizeof(augmented_args.filename.value)) {
len -= sizeof(augmented_args.filename.value) -
augmented_args.filename.size;
len &= sizeof(augmented_args.filename.value) - 1;
}
} else {
I use 6 to mean "hey, this syscall doesn't have any string argument, don't
bother with it".
- Arnaldo
