Re: [PATCH 02/11] target: report too-small parameter lists everywhere

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

On Fri, 2012-09-07 at 17:30 +0200, Paolo Bonzini wrote:
> Several places were not checking that the parameter list length
> was large enough, and thus accessing invalid memory.  Zero-length
> parameter lists are just a special case of this.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---

So I think this looks like reasonable for-3.6 material as well.

Roland, do you have any objections to this..?

>  drivers/target/target_core_alua.c   |    7 +++++++
>  drivers/target/target_core_iblock.c |   17 +++++++++++++++--
>  drivers/target/target_core_pr.c     |    8 ++++++++
>  3 files changed, 30 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
> index 9179997..41641ba 100644
> --- a/drivers/target/target_core_alua.c
> +++ b/drivers/target/target_core_alua.c
> @@ -218,6 +218,13 @@ int target_emulate_set_target_port_groups(struct se_cmd *cmd)
>  		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
>  		return -EINVAL;
>  	}
> +	if (cmd->data_length < 4) {
> +		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
> +			" small\n", cmd->data_length);
> +		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
> +		return -EINVAL;
> +	}
> +
>  	buf = transport_kmap_data_sg(cmd);
>  
>  	/*
> diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
> index 76db75e..9ba4954 100644
> --- a/drivers/target/target_core_iblock.c
> +++ b/drivers/target/target_core_iblock.c
> @@ -325,17 +325,30 @@ static int iblock_execute_unmap(struct se_cmd *cmd)
>  	struct iblock_dev *ibd = dev->dev_ptr;
>  	unsigned char *buf, *ptr = NULL;
>  	sector_t lba;
> -	int size = cmd->data_length;
> +	int size;
>  	u32 range;
>  	int ret = 0;
>  	int dl, bd_dl;
>  
> +	if (cmd->data_length < 8) {
> +		pr_warn("UNMAP parameter list length %u too small\n",
> +			cmd->data_length);
> +		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
> +		return -EINVAL;
> +	}
> +
>  	buf = transport_kmap_data_sg(cmd);
>  
>  	dl = get_unaligned_be16(&buf[0]);
>  	bd_dl = get_unaligned_be16(&buf[2]);
>  
> -	size = min(size - 8, bd_dl);
> +	size = cmd->data_length - 8;
> +	if (bd_dl > size)
> +		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
> +			cmd->data_length, bd_dl);
> +	else
> +		size = bd_dl;
> +
>  	if (size / 16 > dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count) {
>  		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
>  		ret = -EINVAL;
> diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
> index 1e94650..956c84c 100644
> --- a/drivers/target/target_core_pr.c
> +++ b/drivers/target/target_core_pr.c
> @@ -1540,6 +1540,14 @@ static int core_scsi3_decode_spec_i_port(
>  	tidh_new->dest_local_nexus = 1;
>  	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
>  
> +	if (cmd->data_length < 28) {
> +		pr_warn("SPC-PR: Received PR OUT parameter list"
> +			" length too small: %u\n", cmd->data_length);
> +		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
>  	buf = transport_kmap_data_sg(cmd);
>  	/*
>  	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,