Re: [PATCH 1/3] Smack: fix behavior of smack_inode_listsecurity

[Casey Schaufler <casey@schaufler-ca.com>]

On 8/7/2014 9:52 AM, Konstantin Khlebnikov wrote:
> Security operation ->inode_listsecurity is used for generating list of
> available extended attributes for syscall listxattr. Currently it's used
> only in nfs4 or if filesystem doesn't provide i_op->listxattr.
>
> The list is the set of NULL-terminated names, one after the other.
> This method must include zero byte at the and into result.
>
> Also this function must return length even if string does not fit into
> output buffer or it is NULL, see similar method in selinux and man listxattr.
>
> Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>

I plan to ack this patch set once I've run them through my tests.

> ---
>  security/smack/smack_lsm.c |    9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index e6ab307..b11ab23 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -1122,13 +1122,12 @@ static int smack_inode_getsecurity(const struct inode *inode,
>  static int smack_inode_listsecurity(struct inode *inode, char *buffer,
>  				    size_t buffer_size)
>  {
> -	int len = strlen(XATTR_NAME_SMACK);
> +	int len = sizeof(XATTR_NAME_SMACK);
>  
> -	if (buffer != NULL && len <= buffer_size) {
> +	if (buffer != NULL && len <= buffer_size)
>  		memcpy(buffer, XATTR_NAME_SMACK, len);
> -		return len;
> -	}
> -	return -EINVAL;
> +
> +	return len;
>  }
>  
>  /**
>
>