Re: [PATCH] coccinelle: misc: add array_size_dup script to detect missed overlow checks

From: Kees Cook
Date: Wed Jun 17 2020 - 14:15:11 EST


On Mon, Jun 15, 2020 at 01:20:45PM +0300, Denis Efremov wrote:
> +@as@
> +expression E1, E2;
> +@@
> +
> +array_size(E1, E2)

BTW, is there a way yet in Coccinelle to match a fully qualified (?)
identifier? For example, if I have two lines in C:

A)
array_size(variable, 5);
B)
array_size(instance->member.size, 5);
C)
array_size(instance->member.size + 1, 5);
D)
array_size(function_call(variable), 5);


This matches A, B, C, and D:

@@
expression ARG1;
expression ARG2;
@@

array_size(ARG1, ARG2);


This matches only A:

@@
identifier ARG1;
expression ARG2;
@@

array_size(ARG1, ARG2);


How do I get something to match A and B but not C and D (i.e. I do not
want to match any operations, function calls, etc, only a variable,
which may be identified through dereference, array index, or struct
member access.)


--
Kees Cook