Re: [cocci] __free() attribute inhibits matching?

[Kees Cook <kees@kernel.org>]

On Tue, Mar 18, 2025 at 06:56:40PM +0100, Julia Lawall wrote:
> I think you want
> 
> Expression *m;
> 
> A->@m b
> 
> B would be an identifier

But how does "B" get correctly type restricted? (Or in my example,
"NAME"?)

I tried:

@direct depends on !(file in "tools") && !(file in "samples")@
type TYPE;
TYPE *P;
TYPE *MEMBER;
TYPE INST;
identifier NAME;
expression COMP;
identifier ALLOC =~ "^kv?[mz]alloc";
fresh identifier ALLOC_OBJ = ALLOC ## "_obj";
@@

       \(\(P\|COMP.@MEMBER NAME\|COMP->@MEMBER NAME\) \& VAR\)
-       = ALLOC((\(sizeof(*VAR)\|sizeof(TYPE)\|sizeof(INST)\)), GFP);
+       = ALLOC_OBJ(*VAR, GFP);

This parses, but don't match (from crypto/asymmetric_keys/x509_cert_parser.c):

	cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);

But does match (via "P"):

	cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);

/me continues to scratch head


-- 
Kees Cook