Re: [PATCH v5 02/23] ima: Align ima_file_mprotect() definition with LSM infrastructure

[Casey Schaufler]

On 11/7/2023 5:39 AM, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>

Reviewed-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>

> ---
>  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 910a2f11a906..b66353f679e8 100644
> --- a/include/linux/ima.h
> +++ b/include/linux/ima.h
> @@ -23,7 +23,8 @@ 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);
> +extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
> +			     unsigned long prot);
>  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);
> @@ -84,7 +85,7 @@ 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 cc1217ac2c6f..b3f5e8401056 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -455,7 +455,8 @@ 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
> @@ -465,7 +466,8 @@ 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 d7b15ea67c3f..c87ba1bbd7dc 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2819,7 +2819,7 @@ 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);
>  }
>  
>  /**