[Devel] [PATCH v2] fs/fuse kio: deny unavailable ioctl's in kio

[Kirill Tkhai]

On 26.12.2018 11:59, Pavel Butsykin wrote:
> There are some ioctl's that were made to service the kio module, and they
> should not be available to user app.
> 
> Also there are two ioctls PCS_IOC_NOCSUMONREAD and PCS_IOC_NOWRITEDELAY that
> must be handled in kio, otherwise they are meaningless. So let's return
> -EOPNOTSUPP unless we implement them in kio.
> 
> Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>

Reviewed-by: Kirill Tkhai <ktkhai at virtuozzo.com>

> ---
>  fs/fuse/fuse_i.h                   |  2 ++
>  fs/fuse/kio/pcs/pcs_fuse_kdirect.c | 27 ++++++++++++++++++++++++---
>  fs/fuse/kio/pcs/pcs_ioctl.h        |  5 +++++
>  3 files changed, 31 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> index d7dd571c08f6..4c27bfa0e74d 100644
> --- a/fs/fuse/fuse_i.h
> +++ b/fs/fuse/fuse_i.h
> @@ -301,6 +301,7 @@ struct fuse_io_priv {
>   * FR_FINISHED:		request is finished
>   * FR_PRIVATE:		request is on private list
>   * FR_NONBLOCKING:	non-blocking request (only needed for KIO)
> + * FR_KIO_INTERNAL:	request initiated by KIO
>   */
>  enum fuse_req_flag {
>  	FR_ISREPLY,
> @@ -315,6 +316,7 @@ enum fuse_req_flag {
>  	FR_FINISHED,
>  	FR_PRIVATE,
>  	FR_NONBLOCKING,
> +	FR_KIO_INTERNAL,
>  };
>  
>  /**
> diff --git a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
> index 89866370a341..cdd4fe578128 100644
> --- a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
> +++ b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
> @@ -156,6 +156,7 @@ int kpcs_conn_init(struct fuse_conn *fc)
>  	}
>  
>  	__set_bit(FR_BACKGROUND, &req->flags);
> +	__set_bit(FR_KIO_INTERNAL, &req->flags);
>  	memset(&req->misc.ioctl, 0, sizeof(req->misc.ioctl));
>  	/* filehandle and nodeid are null, but this is OK */
>  	inarg = &req->misc.ioctl.in;
> @@ -218,6 +219,7 @@ static int fuse_pcs_getfileinfo(struct fuse_conn *fc, struct file *file,
>  	if (IS_ERR(req))
>  		return PTR_ERR(req);
>  
> +	__set_bit(FR_KIO_INTERNAL, &req->flags);
>  	memset(&req->misc.ioctl, 0, sizeof(req->misc.ioctl));
>  	inarg = &req->misc.ioctl.in;
>  	outarg = &req->misc.ioctl.out;
> @@ -269,6 +271,7 @@ static int fuse_pcs_kdirect_claim_op(struct fuse_conn *fc, struct file *file,
>  	if (IS_ERR(req))
>  		return PTR_ERR(req);
>  
> +	__set_bit(FR_KIO_INTERNAL, &req->flags);
>  	memset(&req->misc.ioctl, 0, sizeof(req->misc.ioctl));
>  	inarg = &req->misc.ioctl.in;
>  	outarg = &req->misc.ioctl.out;
> @@ -470,6 +473,7 @@ int fuse_map_resolve(struct pcs_map_entry *m, int direction)
>  		return PTR_ERR(req);
>  	}
>  
> +	__set_bit(FR_KIO_INTERNAL, &req->flags);
>  	memset(&req->misc.ioctl, 0, sizeof(req->misc.ioctl));
>  	inarg = &req->misc.ioctl.in;
>  	outarg = &req->misc.ioctl.out;
> @@ -601,6 +605,7 @@ int fuse_pcs_csconn_send(struct fuse_conn *fc, struct pcs_rpc *ep, int flags)
>  		return PTR_ERR(req);
>  	}
>  
> +	__set_bit(FR_KIO_INTERNAL, &req->flags);
>  	memset(&req->misc.ioctl, 0, sizeof(req->misc.ioctl));
>  	inarg = &req->misc.ioctl.in;
>  	outarg = &req->misc.ioctl.out;
> @@ -1084,6 +1089,9 @@ static int pcs_kio_classify_req(struct fuse_conn *fc, struct fuse_req *req, bool
>  {
>  	struct fuse_inode *fi = get_fuse_inode(req->io_inode);
>  
> +	if (test_bit(FR_KIO_INTERNAL, &req->flags))
> +		return 1;
> +
>  	switch (req->in.h.opcode) {
>  	case FUSE_READ:
>  	case FUSE_WRITE:
> @@ -1110,9 +1118,22 @@ static int pcs_kio_classify_req(struct fuse_conn *fc, struct fuse_req *req, bool
>  	case FUSE_IOCTL: {
>  		struct fuse_ioctl_in const *inarg = req->in.args[0].value;
>  
> -		if (inarg->cmd != FS_IOC_FIEMAP)
> -			return 1;
> -
> +		switch (inarg->cmd) {
> +			case FS_IOC_FIEMAP:
> +				break;
> +			case PCS_IOC_NOCSUMONREAD:
> +			case PCS_IOC_NOWRITEDELAY:
> +				return -EOPNOTSUPP;
> +			case PCS_IOC_INIT_KDIRECT:
> +			case PCS_IOC_CSCONN:
> +			case PCS_IOC_GETFILEINFO:
> +			case PCS_IOC_KDIRECT_CLAIM:
> +			case PCS_IOC_KDIRECT_RELEASE:
> +			case PCS_IOC_GETMAP:
> +				return -EPERM;
> +			default:
> +				return 1;
> +		}
>  		break;
>  	}
>  	default:
> diff --git a/fs/fuse/kio/pcs/pcs_ioctl.h b/fs/fuse/kio/pcs/pcs_ioctl.h
> index 5cf40e35f881..8fe1aca9ef12 100644
> --- a/fs/fuse/kio/pcs/pcs_ioctl.h
> +++ b/fs/fuse/kio/pcs/pcs_ioctl.h
> @@ -78,6 +78,11 @@ struct pcs_ioc_csconn
>  #define PCS_IOC_CS_REOPEN	(PCS_IOC_CS_OPEN|PCS_IOC_CS_CLOSE)
>  };
>  
> +#define PCS_IOC_NOCSUMONREAD	_IOW('V',3,u32)
> +# define PCS_IOC_NOCSUMONREAD_DATA	1
> +# define PCS_IOC_NOCSUMONREAD_METADATA	2
> +#define PCS_IOC_NOWRITEDELAY	_IOW('V',4,u32)
> +
>  #define PCS_IOC_INIT_KDIRECT	_IOR('V',32, struct pcs_ioc_init_kdirect)
>  #define PCS_IOC_CSCONN		_IOR('V',33, struct pcs_ioc_csconn)
>  #define PCS_IOC_GETFILEINFO	_IOR('V',34, struct pcs_ioc_fileinfo)
>