Re: [Qemu-devel] [PATCH 2/4] scsi-generic: avoid out-of-bounds access to VPD page list

[Daniel Henrique Barboza <danielhb413@gmail.com>]

On 10/29/18 2:34 PM, Paolo Bonzini wrote:
> A device can report an excessive number of VPD pages when asked for a
> list; this can cause an out-of-bounds access to buf in
> scsi_generic_set_vpd_bl_emulation.  It should not happen, but
> it is technically not incorrect so handle it: do not check any byte
> past the allocation length that was sent to the INQUIRY command.
>
> Reported-by: Max Reitz <mreitz@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---

Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>

>   hw/scsi/scsi-generic.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
> index aebb7cdd82..c5497bbea8 100644
> --- a/hw/scsi/scsi-generic.c
> +++ b/hw/scsi/scsi-generic.c
> @@ -538,7 +538,7 @@ static void scsi_generic_set_vpd_bl_emulation(SCSIDevice *s)
>       }
>   
>       page_len = buf[3];
> -    for (i = 4; i < page_len + 4; i++) {
> +    for (i = 4; i < MIN(sizeof(buf), page_len + 4); i++) {
>           if (buf[i] == 0xb0) {
>               s->needs_vpd_bl_emulation = false;
>               return;