RE: [PATCH] ima: Fix misuse of dereference of pointer in template_desc_init_fields()

From: Roberto Sassu
Date: Mon Nov 14 2022 - 03:38:06 EST


> From: Xiujianfeng
> Sent: Saturday, November 12, 2022 10:27 AM
> The input parameter @fields is type of struct ima_template_field ***, so
> when allocates array memory for @fields, the size of element should be
> sizeof(**field) instead of sizeof(*field).
>
> Actually the original code would not cause any runtime error, but it's
> better to make it logically right.
>
> Fixes: adf53a778a0a ("ima: new templates management mechanism")
> Signed-off-by: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>

Reviewed-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>

Thanks

Roberto

> ---
> security/integrity/ima/ima_template.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/security/integrity/ima/ima_template.c
> b/security/integrity/ima/ima_template.c
> index 49f0626928a1..04c49f05cb74 100644
> --- a/security/integrity/ima/ima_template.c
> +++ b/security/integrity/ima/ima_template.c
> @@ -245,11 +245,11 @@ int template_desc_init_fields(const char
> *template_fmt,
> }
>
> if (fields && num_fields) {
> - *fields = kmalloc_array(i, sizeof(*fields), GFP_KERNEL);
> + *fields = kmalloc_array(i, sizeof(**fields), GFP_KERNEL);
> if (*fields == NULL)
> return -ENOMEM;
>
> - memcpy(*fields, found_fields, i * sizeof(*fields));
> + memcpy(*fields, found_fields, i * sizeof(**fields));
> *num_fields = i;
> }
>
> --
> 2.17.1