Re: [PATCH v3 04/25] ima: Align ima_file_mprotect() definition with LSM infrastructure

[Mimi Zohar <zohar@linux.ibm.com>]

On Mon, 2023-09-04 at 15:33 +0200, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
> 
> Change ima_file_mprotect() definition, so that it can be registered
> as implementation of the file_mprotect hook.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
> ---
>  include/linux/ima.h               | 5 +++--
>  security/integrity/ima/ima_main.c | 6 ++++--
>  security/security.c               | 2 +-
>  3 files changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/ima.h b/include/linux/ima.h
> index 893c3b98b4d0..56e72c0beb96 100644
> --- a/include/linux/ima.h
> +++ b/include/linux/ima.h
> @@ -24,7 +24,8 @@ extern void ima_post_create_tmpfile(struct mnt_idmap *idmap,
>  extern void ima_file_free(struct file *file);
>  extern int ima_file_mmap(struct file *file, unsigned long reqprot,
>  			 unsigned long prot, unsigned long flags);
> -extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot);
> +int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
> +		      unsigned long prot);

"extern" is needed here and similarly in 5/25.

Mimi

>  extern int ima_load_data(enum kernel_load_data_id id, bool contents);
>  extern int ima_post_load_data(char *buf, loff_t size,
>  			      enum kernel_load_data_id id, char *description);
> @@ -88,7 +89,7 @@ static inline int ima_file_mmap(struct file *file, unsigned long reqprot,
>  }
>  
>  static inline int ima_file_mprotect(struct vm_area_struct *vma,
> -				    unsigned long prot)
> +				    unsigned long reqprot, unsigned long prot)
>  {
>  	return 0;
>  }
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 52e742d32f4b..e9e2a3ad25a1 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -441,7 +441,8 @@ int ima_file_mmap(struct file *file, unsigned long reqprot,
>  /**
>   * ima_file_mprotect - based on policy, limit mprotect change
>   * @vma: vm_area_struct protection is set to
> - * @prot: contains the protection that will be applied by the kernel.
> + * @reqprot: protection requested by the application
> + * @prot: protection that will be applied by the kernel
>   *
>   * Files can be mmap'ed read/write and later changed to execute to circumvent
>   * IMA's mmap appraisal policy rules.  Due to locking issues (mmap semaphore
> @@ -451,7 +452,8 @@ int ima_file_mmap(struct file *file, unsigned long reqprot,
>   *
>   * On mprotect change success, return 0.  On failure, return -EACESS.
>   */
> -int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
> +int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
> +		      unsigned long prot)
>  {
>  	struct ima_template_desc *template = NULL;
>  	struct file *file;
> diff --git a/security/security.c b/security/security.c
> index 96f2c68a1571..dffb67e6e119 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2721,7 +2721,7 @@ int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
>  	ret = call_int_hook(file_mprotect, 0, vma, reqprot, prot);
>  	if (ret)
>  		return ret;
> -	return ima_file_mprotect(vma, prot);
> +	return ima_file_mprotect(vma, reqprot, prot);
>  }
>  
>  /**