Re: [PATCH] ima: fix mprotect checking

[Lakshmi Ramasubramanian <nramas@linux.microsoft.com>]

On 6/11/20 4:19 AM, Mimi Zohar wrote:

> Make sure IMA is enabled before checking mprotect change.  Addresses
> report of a 3.7% regression of boot-time.dhcp.
> 
> Fixes: 8eb613c0b8f1 ("ima: verify mprotect change is consistent with mmap policy")
> Reported-by: kernel test robot <rong.a.chen@intel.com>
> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
> ---
>   security/integrity/ima/ima_main.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 800fb3bba418..c1583d98c5e5 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -419,7 +419,8 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
>   	int pcr;
>   
>   	/* Is mprotect making an mmap'ed file executable? */
> -	if (!vma->vm_file || !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC))
> +	if (!(ima_policy_flag & IMA_APPRAISE) || !vma->vm_file ||
> +	    !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC))
>   		return 0;
>   
>   	security_task_getsecid(current, &secid);
> 

Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>