Re: [PATCH 2/2] [PATCH v1 2/2] sd: Fixing interpretation of VPD B9h length

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 6/1/22 02:50, Tyler Erickson wrote:
> Fixing the interpretation of the length of the B9h VPD page
> (concurrent positioning ranges). Adding 4 is necessary as
> the first 4 bytes of the page is the header with page number
> and length information. Adding 3 was likely a misinterpretation
> of the SBC-5 specification which sets all offsets starting at zero.
> 
> This fixes the error in dmesg:
> [ 9.014456] sd 1:0:0:0: [sda] Invalid Concurrent Positioning Ranges VPD page
> 
> Signed-off-by: Tyler Erickson <tyler.erickson@seagate.com>
> Reviewed-by: Muhammad Ahmad <muhammad.ahmad@seagate.com>
> Tested-by: Michael English <michael.english@seagate.com>

This needs a fixes tag and cc stable. Your patch format is also starnge.
It is missing the "---" separator after the tags. This is not going to
apply. Did you generate this with git format-patch ?

> 
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index dc6e55761fd1..14867e8cd687 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -3067,7 +3067,7 @@ static void sd_read_cpr(struct scsi_disk *sdkp)
>  		goto out;
>  
>  	/* We must have at least a 64B header and one 32B range descriptor */
> -	vpd_len = get_unaligned_be16(&buffer[2]) + 3;
> +	vpd_len = get_unaligned_be16(&buffer[2]) + 4;
>  	if (vpd_len > buf_len || vpd_len < 64 + 32 || (vpd_len & 31)) {
>  		sd_printk(KERN_ERR, sdkp,
>  			  "Invalid Concurrent Positioning Ranges VPD page\n");


-- 
Damien Le Moal
Western Digital Research