scsi-generic: avoid invalid access to struct when emulating block limits

Emulation of the block limits VPD page called back into scsi-disk.c,
which however expected the request to be for a SCSIDiskState and
accessed a scsi-generic device outside the bounds of its struct
(namely to retrieve s->max_unmap_size and s->max_io_size).

To avoid this, move the emulation code to a separate function that
takes a new SCSIBlockLimits struct and marshals it into the VPD
response format.

Reported-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2018-10-23 00:43:51 +02:00
parent 57dbb58d80
commit 3d4a8bf0ee
6 changed files with 104 additions and 84 deletions

View file

@ -33,6 +33,7 @@ do { printf("scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "hw/scsi/scsi.h"
#include "hw/scsi/emulation.h"
#include "scsi/constants.h"
#include "sysemu/sysemu.h"
#include "sysemu/block-backend.h"
@ -589,7 +590,7 @@ static uint8_t *scsi_get_buf(SCSIRequest *req)
return (uint8_t *)r->iov.iov_base;
}
int scsi_disk_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf)
static int scsi_disk_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf)
{
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
uint8_t page_code = req->cmd.buf[2];
@ -691,89 +692,36 @@ int scsi_disk_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf)
}
case 0xb0: /* block limits */
{
unsigned int unmap_sectors =
s->qdev.conf.discard_granularity / s->qdev.blocksize;
unsigned int min_io_size =
s->qdev.conf.min_io_size / s->qdev.blocksize;
unsigned int opt_io_size =
s->qdev.conf.opt_io_size / s->qdev.blocksize;
unsigned int max_unmap_sectors =
s->max_unmap_size / s->qdev.blocksize;
unsigned int max_io_sectors =
s->max_io_size / s->qdev.blocksize;
SCSIBlockLimits bl = {};
if (s->qdev.type == TYPE_ROM) {
DPRINTF("Inquiry (EVPD[%02X] not supported for CDROM\n",
page_code);
return -1;
}
bl.wsnz = 1;
bl.unmap_sectors =
s->qdev.conf.discard_granularity / s->qdev.blocksize;
bl.min_io_size =
s->qdev.conf.min_io_size / s->qdev.blocksize;
bl.opt_io_size =
s->qdev.conf.opt_io_size / s->qdev.blocksize;
bl.max_unmap_sectors =
s->max_unmap_size / s->qdev.blocksize;
bl.max_io_sectors =
s->max_io_size / s->qdev.blocksize;
/* 255 descriptors fit in 4 KiB with an 8-byte header */
bl.max_unmap_descr = 255;
if (s->qdev.type == TYPE_DISK) {
int max_transfer_blk = blk_get_max_transfer(s->qdev.conf.blk);
int max_io_sectors_blk =
max_transfer_blk / s->qdev.blocksize;
max_io_sectors =
MIN_NON_ZERO(max_io_sectors_blk, max_io_sectors);
/* min_io_size and opt_io_size can't be greater than
* max_io_sectors */
if (min_io_size) {
min_io_size = MIN(min_io_size, max_io_sectors);
}
if (opt_io_size) {
opt_io_size = MIN(opt_io_size, max_io_sectors);
}
bl.max_io_sectors =
MIN_NON_ZERO(max_io_sectors_blk, bl.max_io_sectors);
}
/* required VPD size with unmap support */
buflen = 0x40;
memset(outbuf + 4, 0, buflen - 4);
outbuf[4] = 0x1; /* wsnz */
/* optimal transfer length granularity */
outbuf[6] = (min_io_size >> 8) & 0xff;
outbuf[7] = min_io_size & 0xff;
/* maximum transfer length */
outbuf[8] = (max_io_sectors >> 24) & 0xff;
outbuf[9] = (max_io_sectors >> 16) & 0xff;
outbuf[10] = (max_io_sectors >> 8) & 0xff;
outbuf[11] = max_io_sectors & 0xff;
/* optimal transfer length */
outbuf[12] = (opt_io_size >> 24) & 0xff;
outbuf[13] = (opt_io_size >> 16) & 0xff;
outbuf[14] = (opt_io_size >> 8) & 0xff;
outbuf[15] = opt_io_size & 0xff;
/* max unmap LBA count, default is 1GB */
outbuf[20] = (max_unmap_sectors >> 24) & 0xff;
outbuf[21] = (max_unmap_sectors >> 16) & 0xff;
outbuf[22] = (max_unmap_sectors >> 8) & 0xff;
outbuf[23] = max_unmap_sectors & 0xff;
/* max unmap descriptors, 255 fit in 4 kb with an 8-byte header */
outbuf[24] = 0;
outbuf[25] = 0;
outbuf[26] = 0;
outbuf[27] = 255;
/* optimal unmap granularity */
outbuf[28] = (unmap_sectors >> 24) & 0xff;
outbuf[29] = (unmap_sectors >> 16) & 0xff;
outbuf[30] = (unmap_sectors >> 8) & 0xff;
outbuf[31] = unmap_sectors & 0xff;
/* max write same size */
outbuf[36] = 0;
outbuf[37] = 0;
outbuf[38] = 0;
outbuf[39] = 0;
outbuf[40] = (max_io_sectors >> 24) & 0xff;
outbuf[41] = (max_io_sectors >> 16) & 0xff;
outbuf[42] = (max_io_sectors >> 8) & 0xff;
outbuf[43] = max_io_sectors & 0xff;
buflen += scsi_emulate_block_limits(outbuf + buflen, &bl);
break;
}
case 0xb1: /* block device characteristics */