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xemu/hw/usb/dev-storage.c
John Millikin fe9d8927e2 scsi: Add buf_len parameter to scsi_req_new() 
When a SCSI command is received from the guest, the CDB length implied
by the first byte might exceed the number of bytes the guest sent. In
this case scsi_req_new() will read uninitialized data, causing
unpredictable behavior.

Adds the buf_len parameter to scsi_req_new() and plumbs it through the
call stack.

Signed-off-by: John Millikin <john@john-millikin.com>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1127
Message-Id: <20220817053458.698416-1-john@john-millikin.com>
[Fill in correct length for adapters other than ESP. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-01 07:42:37 +02:00

590 lines
17 KiB
C
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/*
* USB Mass Storage Device emulation
*
* Copyright (c) 2006 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed under the LGPL.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "qemu/config-file.h"
#include "hw/usb.h"
#include "hw/usb/msd.h"
#include "desc.h"
#include "hw/qdev-properties.h"
#include "hw/scsi/scsi.h"
#include "migration/vmstate.h"
#include "qemu/cutils.h"
#include "qom/object.h"
#include "trace.h"
/* USB requests. */
#define MassStorageReset 0xff
#define GetMaxLun 0xfe
struct usb_msd_cbw {
uint32_t sig;
uint32_t tag;
uint32_t data_len;
uint8_t flags;
uint8_t lun;
uint8_t cmd_len;
uint8_t cmd[16];
};
enum {
STR_MANUFACTURER = 1,
STR_PRODUCT,
STR_SERIALNUMBER,
STR_CONFIG_FULL,
STR_CONFIG_HIGH,
STR_CONFIG_SUPER,
};
static const USBDescStrings desc_strings = {
[STR_MANUFACTURER] = "QEMU",
[STR_PRODUCT] = "QEMU USB HARDDRIVE",
[STR_SERIALNUMBER] = "1",
[STR_CONFIG_FULL] = "Full speed config (usb 1.1)",
[STR_CONFIG_HIGH] = "High speed config (usb 2.0)",
[STR_CONFIG_SUPER] = "Super speed config (usb 3.0)",
};
static const USBDescIface desc_iface_full = {
.bInterfaceNumber = 0,
.bNumEndpoints = 2,
.bInterfaceClass = USB_CLASS_MASS_STORAGE,
.bInterfaceSubClass = 0x06, /* SCSI */
.bInterfaceProtocol = 0x50, /* Bulk */
.eps = (USBDescEndpoint[]) {
{
.bEndpointAddress = USB_DIR_IN | 0x01,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = 64,
},{
.bEndpointAddress = USB_DIR_OUT | 0x02,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = 64,
},
}
};
static const USBDescDevice desc_device_full = {
.bcdUSB = 0x0200,
.bMaxPacketSize0 = 8,
.bNumConfigurations = 1,
.confs = (USBDescConfig[]) {
{
.bNumInterfaces = 1,
.bConfigurationValue = 1,
.iConfiguration = STR_CONFIG_FULL,
.bmAttributes = USB_CFG_ATT_ONE | USB_CFG_ATT_SELFPOWER,
.nif = 1,
.ifs = &desc_iface_full,
},
},
};
static const USBDescIface desc_iface_high = {
.bInterfaceNumber = 0,
.bNumEndpoints = 2,
.bInterfaceClass = USB_CLASS_MASS_STORAGE,
.bInterfaceSubClass = 0x06, /* SCSI */
.bInterfaceProtocol = 0x50, /* Bulk */
.eps = (USBDescEndpoint[]) {
{
.bEndpointAddress = USB_DIR_IN | 0x01,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = 512,
},{
.bEndpointAddress = USB_DIR_OUT | 0x02,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = 512,
},
}
};
static const USBDescDevice desc_device_high = {
.bcdUSB = 0x0200,
.bMaxPacketSize0 = 64,
.bNumConfigurations = 1,
.confs = (USBDescConfig[]) {
{
.bNumInterfaces = 1,
.bConfigurationValue = 1,
.iConfiguration = STR_CONFIG_HIGH,
.bmAttributes = USB_CFG_ATT_ONE | USB_CFG_ATT_SELFPOWER,
.nif = 1,
.ifs = &desc_iface_high,
},
},
};
static const USBDescIface desc_iface_super = {
.bInterfaceNumber = 0,
.bNumEndpoints = 2,
.bInterfaceClass = USB_CLASS_MASS_STORAGE,
.bInterfaceSubClass = 0x06, /* SCSI */
.bInterfaceProtocol = 0x50, /* Bulk */
.eps = (USBDescEndpoint[]) {
{
.bEndpointAddress = USB_DIR_IN | 0x01,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = 1024,
.bMaxBurst = 15,
},{
.bEndpointAddress = USB_DIR_OUT | 0x02,
.bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = 1024,
.bMaxBurst = 15,
},
}
};
static const USBDescDevice desc_device_super = {
.bcdUSB = 0x0300,
.bMaxPacketSize0 = 9,
.bNumConfigurations = 1,
.confs = (USBDescConfig[]) {
{
.bNumInterfaces = 1,
.bConfigurationValue = 1,
.iConfiguration = STR_CONFIG_SUPER,
.bmAttributes = USB_CFG_ATT_ONE | USB_CFG_ATT_SELFPOWER,
.nif = 1,
.ifs = &desc_iface_super,
},
},
};
static const USBDesc desc = {
.id = {
.idVendor = 0x46f4, /* CRC16() of "QEMU" */
.idProduct = 0x0001,
.bcdDevice = 0,
.iManufacturer = STR_MANUFACTURER,
.iProduct = STR_PRODUCT,
.iSerialNumber = STR_SERIALNUMBER,
},
.full = &desc_device_full,
.high = &desc_device_high,
.super = &desc_device_super,
.str = desc_strings,
};
static void usb_msd_copy_data(MSDState *s, USBPacket *p)
{
uint32_t len;
len = p->iov.size - p->actual_length;
if (len > s->scsi_len)
len = s->scsi_len;
usb_packet_copy(p, scsi_req_get_buf(s->req) + s->scsi_off, len);
s->scsi_len -= len;
s->scsi_off += len;
if (len > s->data_len) {
len = s->data_len;
}
s->data_len -= len;
if (s->scsi_len == 0 || s->data_len == 0) {
scsi_req_continue(s->req);
}
}
static void usb_msd_send_status(MSDState *s, USBPacket *p)
{
int len;
trace_usb_msd_send_status(s->csw.status, le32_to_cpu(s->csw.tag),
p->iov.size);
assert(s->csw.sig == cpu_to_le32(0x53425355));
len = MIN(sizeof(s->csw), p->iov.size);
usb_packet_copy(p, &s->csw, len);
memset(&s->csw, 0, sizeof(s->csw));
}
static void usb_msd_packet_complete(MSDState *s)
{
USBPacket *p = s->packet;
/* Set s->packet to NULL before calling usb_packet_complete
because another request may be issued before
usb_packet_complete returns. */
trace_usb_msd_packet_complete();
s->packet = NULL;
usb_packet_complete(&s->dev, p);
}
void usb_msd_transfer_data(SCSIRequest *req, uint32_t len)
{
MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
USBPacket *p = s->packet;
assert((s->mode == USB_MSDM_DATAOUT) == (req->cmd.mode == SCSI_XFER_TO_DEV));
s->scsi_len = len;
s->scsi_off = 0;
if (p) {
usb_msd_copy_data(s, p);
p = s->packet;
if (p && p->actual_length == p->iov.size) {
p->status = USB_RET_SUCCESS; /* Clear previous ASYNC status */
usb_msd_packet_complete(s);
}
}
}
void usb_msd_command_complete(SCSIRequest *req, size_t resid)
{
MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
USBPacket *p = s->packet;
trace_usb_msd_cmd_complete(req->status, req->tag);
s->csw.sig = cpu_to_le32(0x53425355);
s->csw.tag = cpu_to_le32(req->tag);
s->csw.residue = cpu_to_le32(s->data_len);
s->csw.status = req->status != 0;
if (s->packet) {
if (s->data_len == 0 && s->mode == USB_MSDM_DATAOUT) {
/* A deferred packet with no write data remaining must be
the status read packet. */
usb_msd_send_status(s, p);
s->mode = USB_MSDM_CBW;
} else if (s->mode == USB_MSDM_CSW) {
usb_msd_send_status(s, p);
s->mode = USB_MSDM_CBW;
} else {
if (s->data_len) {
int len = (p->iov.size - p->actual_length);
usb_packet_skip(p, len);
if (len > s->data_len) {
len = s->data_len;
}
s->data_len -= len;
}
if (s->data_len == 0) {
s->mode = USB_MSDM_CSW;
}
}
p->status = USB_RET_SUCCESS; /* Clear previous ASYNC status */
usb_msd_packet_complete(s);
} else if (s->data_len == 0) {
s->mode = USB_MSDM_CSW;
}
scsi_req_unref(req);
s->req = NULL;
}
void usb_msd_request_cancelled(SCSIRequest *req)
{
MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
trace_usb_msd_cmd_cancel(req->tag);
if (req == s->req) {
s->csw.sig = cpu_to_le32(0x53425355);
s->csw.tag = cpu_to_le32(req->tag);
s->csw.status = 1; /* error */
scsi_req_unref(s->req);
s->req = NULL;
s->scsi_len = 0;
}
}
void usb_msd_handle_reset(USBDevice *dev)
{
MSDState *s = (MSDState *)dev;
trace_usb_msd_reset();
if (s->req) {
scsi_req_cancel(s->req);
}
assert(s->req == NULL);
if (s->packet) {
s->packet->status = USB_RET_STALL;
usb_msd_packet_complete(s);
}
memset(&s->csw, 0, sizeof(s->csw));
s->mode = USB_MSDM_CBW;
}
static void usb_msd_handle_control(USBDevice *dev, USBPacket *p,
int request, int value, int index, int length, uint8_t *data)
{
MSDState *s = (MSDState *)dev;
SCSIDevice *scsi_dev;
int ret, maxlun;
ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
if (ret >= 0) {
return;
}
switch (request) {
case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
break;
/* Class specific requests. */
case ClassInterfaceOutRequest | MassStorageReset:
/* Reset state ready for the next CBW. */
s->mode = USB_MSDM_CBW;
break;
case ClassInterfaceRequest | GetMaxLun:
maxlun = 0;
for (;;) {
scsi_dev = scsi_device_find(&s->bus, 0, 0, maxlun+1);
if (scsi_dev == NULL) {
break;
}
if (scsi_dev->lun != maxlun+1) {
break;
}
maxlun++;
}
trace_usb_msd_maxlun(maxlun);
data[0] = maxlun;
p->actual_length = 1;
break;
default:
p->status = USB_RET_STALL;
break;
}
}
static void usb_msd_cancel_io(USBDevice *dev, USBPacket *p)
{
MSDState *s = USB_STORAGE_DEV(dev);
assert(s->packet == p);
s->packet = NULL;
if (s->req) {
scsi_req_cancel(s->req);
}
}
static void usb_msd_handle_data(USBDevice *dev, USBPacket *p)
{
MSDState *s = (MSDState *)dev;
uint32_t tag;
struct usb_msd_cbw cbw;
uint8_t devep = p->ep->nr;
SCSIDevice *scsi_dev;
uint32_t len;
switch (p->pid) {
case USB_TOKEN_OUT:
if (devep != 2)
goto fail;
switch (s->mode) {
case USB_MSDM_CBW:
if (p->iov.size != 31) {
error_report("usb-msd: Bad CBW size");
goto fail;
}
usb_packet_copy(p, &cbw, 31);
if (le32_to_cpu(cbw.sig) != 0x43425355) {
error_report("usb-msd: Bad signature %08x",
le32_to_cpu(cbw.sig));
goto fail;
}
scsi_dev = scsi_device_find(&s->bus, 0, 0, cbw.lun);
if (scsi_dev == NULL) {
error_report("usb-msd: Bad LUN %d", cbw.lun);
goto fail;
}
tag = le32_to_cpu(cbw.tag);
s->data_len = le32_to_cpu(cbw.data_len);
if (s->data_len == 0) {
s->mode = USB_MSDM_CSW;
} else if (cbw.flags & 0x80) {
s->mode = USB_MSDM_DATAIN;
} else {
s->mode = USB_MSDM_DATAOUT;
}
trace_usb_msd_cmd_submit(cbw.lun, tag, cbw.flags,
cbw.cmd_len, s->data_len);
assert(le32_to_cpu(s->csw.residue) == 0);
s->scsi_len = 0;
s->req = scsi_req_new(scsi_dev, tag, cbw.lun, cbw.cmd, cbw.cmd_len, NULL);
if (s->commandlog) {
scsi_req_print(s->req);
}
len = scsi_req_enqueue(s->req);
if (len) {
scsi_req_continue(s->req);
}
break;
case USB_MSDM_DATAOUT:
trace_usb_msd_data_out(p->iov.size, s->data_len);
if (p->iov.size > s->data_len) {
goto fail;
}
if (s->scsi_len) {
usb_msd_copy_data(s, p);
}
if (le32_to_cpu(s->csw.residue)) {
int len = p->iov.size - p->actual_length;
if (len) {
usb_packet_skip(p, len);
if (len > s->data_len) {
len = s->data_len;
}
s->data_len -= len;
if (s->data_len == 0) {
s->mode = USB_MSDM_CSW;
}
}
}
if (p->actual_length < p->iov.size) {
trace_usb_msd_packet_async();
s->packet = p;
p->status = USB_RET_ASYNC;
}
break;
default:
goto fail;
}
break;
case USB_TOKEN_IN:
if (devep != 1)
goto fail;
switch (s->mode) {
case USB_MSDM_DATAOUT:
if (s->data_len != 0 || p->iov.size < 13) {
goto fail;
}
/* Waiting for SCSI write to complete. */
trace_usb_msd_packet_async();
s->packet = p;
p->status = USB_RET_ASYNC;
break;
case USB_MSDM_CSW:
if (p->iov.size < 13) {
goto fail;
}
if (s->req) {
/* still in flight */
trace_usb_msd_packet_async();
s->packet = p;
p->status = USB_RET_ASYNC;
} else {
usb_msd_send_status(s, p);
s->mode = USB_MSDM_CBW;
}
break;
case USB_MSDM_DATAIN:
trace_usb_msd_data_in(p->iov.size, s->data_len, s->scsi_len);
if (s->scsi_len) {
usb_msd_copy_data(s, p);
}
if (le32_to_cpu(s->csw.residue)) {
int len = p->iov.size - p->actual_length;
if (len) {
usb_packet_skip(p, len);
if (len > s->data_len) {
len = s->data_len;
}
s->data_len -= len;
if (s->data_len == 0) {
s->mode = USB_MSDM_CSW;
}
}
}
if (p->actual_length < p->iov.size && s->mode == USB_MSDM_DATAIN) {
trace_usb_msd_packet_async();
s->packet = p;
p->status = USB_RET_ASYNC;
}
break;
default:
goto fail;
}
break;
default:
fail:
p->status = USB_RET_STALL;
break;
}
}
void *usb_msd_load_request(QEMUFile *f, SCSIRequest *req)
{
MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
/* nothing to load, just store req in our state struct */
assert(s->req == NULL);
scsi_req_ref(req);
s->req = req;
return NULL;
}
static const VMStateDescription vmstate_usb_msd = {
.name = "usb-storage",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_USB_DEVICE(dev, MSDState),
VMSTATE_UINT32(mode, MSDState),
VMSTATE_UINT32(scsi_len, MSDState),
VMSTATE_UINT32(scsi_off, MSDState),
VMSTATE_UINT32(data_len, MSDState),
VMSTATE_UINT32(csw.sig, MSDState),
VMSTATE_UINT32(csw.tag, MSDState),
VMSTATE_UINT32(csw.residue, MSDState),
VMSTATE_UINT8(csw.status, MSDState),
VMSTATE_END_OF_LIST()
}
};
static void usb_msd_class_initfn_common(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
uc->product_desc = "QEMU USB MSD";
uc->usb_desc = &desc;
uc->cancel_packet = usb_msd_cancel_io;
uc->handle_attach = usb_desc_attach;
uc->handle_reset = usb_msd_handle_reset;
uc->handle_control = usb_msd_handle_control;
uc->handle_data = usb_msd_handle_data;
set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
dc->fw_name = "storage";
dc->vmsd = &vmstate_usb_msd;
}
static const TypeInfo usb_storage_dev_type_info = {
.name = TYPE_USB_STORAGE,
.parent = TYPE_USB_DEVICE,
.instance_size = sizeof(MSDState),
.abstract = true,
.class_init = usb_msd_class_initfn_common,
};
static void usb_msd_register_types(void)
{
type_register_static(&usb_storage_dev_type_info);
}
type_init(usb_msd_register_types)
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