Re: [patch] [SCSI] scsi_transport_sas: check for allocation failure

[Douglas Gilbert]

On 13-03-08 07:02 AM, Dan Carpenter wrote:
> Static checkers complain that this allocation isn't checked.  We
> should return zero if the allocation fails.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
> index 1b68142..a022997 100644
> --- a/drivers/scsi/scsi_transport_sas.c
> +++ b/drivers/scsi/scsi_transport_sas.c
> @@ -379,9 +379,12 @@ sas_tlr_supported(struct scsi_device *sdev)
>   {
>   	const int vpd_len = 32;
>   	struct sas_end_device *rdev = sas_sdev_to_rdev(sdev);
> -	char *buffer = kzalloc(vpd_len, GFP_KERNEL);
> +	char *buffer;
>   	int ret = 0;
>
> +	buffer = kzalloc(vpd_len, GFP_KERNEL);
> +	if (!buffer)
> +		goto out;
>   	if (scsi_get_vpd_page(sdev, 0x90, buffer, vpd_len))
>   		goto out;

For 32 bytes, why not use the stack?

unsigned int
sas_tlr_supported(struct scsi_device *sdev)
{
        unsigned char buffer[32];
        struct sas_end_device *rdev = sas_sdev_to_rdev(sdev);
        int ret = 0;

        if (scsi_get_vpd_page(sdev, 0x90, buffer, sizeof(buffer)))
                goto out;

        /*
         * The VPD Protocol Specific Logical Unit page (0x90) for SAS
         * has a 4 byte header and then one descriptor per device port.
         * The TLR bit is at offset 8 on each port descriptor.
         * We take the TLR value in the first descriptor.
         */
        ret = buffer[4 + 8] & 0x01;

 out:
        rdev->tlr_supported = ret;
        return ret;
}


Note the comment is changed.

Doug Gilbert


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