Re: [PATCH v2 4/7] ima: Mark concurrent accesses to the iint pointer in the inode security blob

[Mimi Zohar <zohar@xxxxxxxxxxxxx>]

On Thu, 2024-11-28 at 11:06 +0100, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> 
> Use the READ_ONCE() and WRITE_ONCE() macros to mark concurrent read and
> write accesses to the portion of the inode security blob containing the
> iint pointer.
> 
> Writers are serialized by the iint lock.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>

Thanks, Roberto.

Reviewed-by:  Mimi Zohar <zohar@xxxxxxxxxxxxx>

> ---
>  security/integrity/ima/ima_iint.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
> index fca9db293c79..c763f431fbc1 100644
> --- a/security/integrity/ima/ima_iint.c
> +++ b/security/integrity/ima/ima_iint.c
> @@ -32,7 +32,7 @@ struct ima_iint_cache *ima_iint_find(struct inode *inode)
>  	if (!iint_lock)
>  		return NULL;
>  
> -	return iint_lock->iint;
> +	return READ_ONCE(iint_lock->iint);
>  }
>  
>  #define IMA_MAX_NESTING (FILESYSTEM_MAX_STACK_DEPTH + 1)
> @@ -99,7 +99,7 @@ struct ima_iint_cache *ima_inode_get(struct inode *inode)
>  
>  	lockdep_assert_held(&iint_lock->mutex);
>  
> -	iint = iint_lock->iint;
> +	iint = READ_ONCE(iint_lock->iint);
>  	if (iint)
>  		return iint;
>  
> @@ -109,7 +109,7 @@ struct ima_iint_cache *ima_inode_get(struct inode *inode)
>  
>  	ima_iint_init_always(iint, inode);
>  
> -	iint_lock->iint = iint;
> +	WRITE_ONCE(iint_lock->iint, iint);
>  
>  	return iint;
>  }