Re: [PATCH] ima: Fix warn potential negative subtraction from max

From: Serge E. Hallyn
Date: Thu Dec 21 2017 - 13:00:10 EST


Quoting Vasyl Gomonovych (gomonovych@xxxxxxxxx):
> Found by smatch:
> security/integrity/ima/ima_queue.c:122 ima_add_digest_entry() warn:
> potential negative subtraction from max '(~0)- size'
>
> Signed-off-by: Vasyl Gomonovych <gomonovych@xxxxxxxxx>
> ---
> security/integrity/ima/ima_queue.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
> index a02a86d51102..446018478b81 100644
> --- a/security/integrity/ima/ima_queue.c
> +++ b/security/integrity/ima/ima_queue.c
> @@ -116,7 +116,7 @@ static int ima_add_digest_entry(struct ima_template_entry *entry,
> }
>
> if (binary_runtime_size != ULONG_MAX) {
> - int size;
> + unsigned int size;

Hm, but get_binary_runtime_size() returns an int.

>
> size = get_binary_runtime_size(entry);
> binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ?
> --
> 1.9.1