Re: [Qemu-devel] [PATCH] SCSI: improve the lba-out-of-range tests for read/write/verify

[Paolo Bonzini]

Il 12/07/2012 08:52, Ronnie Sahlberg ha scritto:
> Improve the tests for the LBA to cover more cases, the new test looks like 
> this
>         if (r->req.cmd.lba > r->req.cmd.lba + len
>         ||  r->req.cmd.lba + len > s->qdev.max_lba) {
> 
> For the 16 byte opcodes, the lba is a uint64, so the first check is to make 
> sure that we do not wrap.
> For example if an opcode would specify the LBA:0xffffffffffffffff and LEN:2
> then lba+len would wrap to 1.
> 
> The second part of the test is to verify that ALL requested blocks are 
> available, not just the first one.

Fixed code style for || and applied to scsi-next.

Thanks!

Paolo

> Signed-off-by: Ronnie Sahlberg <address@hidden>
> ---
>  hw/scsi-disk.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
> index b2f3c0c..40c05de 100644
> --- a/hw/scsi-disk.c
> +++ b/hw/scsi-disk.c
> @@ -1558,7 +1558,8 @@ static int32_t scsi_send_command(SCSIRequest *req, 
> uint8_t *buf)
>          if (r->req.cmd.buf[1] & 0xe0) {
>              goto fail;
>          }
> -        if (r->req.cmd.lba > s->qdev.max_lba) {
> +        if (r->req.cmd.lba > r->req.cmd.lba + len
> +        ||  r->req.cmd.lba + len > s->qdev.max_lba) {
>              goto illegal_lba;
>          }
>          r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
> @@ -1581,7 +1582,8 @@ static int32_t scsi_send_command(SCSIRequest *req, 
> uint8_t *buf)
>          if (r->req.cmd.buf[1] & 0xe0) {
>              goto fail;
>          }
> -        if (r->req.cmd.lba > s->qdev.max_lba) {
> +        if (r->req.cmd.lba > r->req.cmd.lba + len
> +        ||  r->req.cmd.lba + len > s->qdev.max_lba) {
>              goto illegal_lba;
>          }
>          r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
>