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authorGerd Hoffmann <kraxel@redhat.com>2022-08-30 08:38:27 +0200
committerGerd Hoffmann <kraxel@redhat.com>2022-09-27 07:32:30 +0200
commit12b69878fc7b4b92b1bbd3959f2c3d4c717881fb (patch)
tree63dc05ce5fb3aba25dffc251980849270a09da7e /hw/usb
parentcea5aa85691d7f26b7ea995417d41a32802691b7 (diff)
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usb/msd: add usb_msd_fatal_error() and fix guest-triggerable assert
Add handler for fatal errors. Moves device into error state where it stops responding until the guest resets it. Guest can send illegal requests where scsi command and usb packet transfer directions are inconsistent. Use the new usb_msd_fatal_error() function instead of assert() in that case. Reported-by: Qiang Liu <cyruscyliu@gmail.com> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Tested-by: Qiang Liu <cyruscyliu@gmail.com> Message-Id: <20220830063827.813053-3-kraxel@redhat.com>
Diffstat (limited to 'hw/usb')
-rw-r--r--hw/usb/dev-storage.c30
-rw-r--r--hw/usb/trace-events1
2 files changed, 30 insertions, 1 deletions
diff --git a/hw/usb/dev-storage.c b/hw/usb/dev-storage.c
index 140ef2a..e3bcffb 100644
--- a/hw/usb/dev-storage.c
+++ b/hw/usb/dev-storage.c
@@ -191,6 +191,23 @@ static void usb_msd_packet_complete(MSDState *s)
usb_packet_complete(&s->dev, p);
}
+static void usb_msd_fatal_error(MSDState *s)
+{
+ trace_usb_msd_fatal_error();
+
+ if (s->packet) {
+ s->packet->status = USB_RET_STALL;
+ usb_msd_packet_complete(s);
+ }
+
+ /*
+ * Guest messed up up device state with illegal requests. Go
+ * ignore any requests until the guests resets the device (and
+ * brings it into a known state that way).
+ */
+ s->needs_reset = true;
+}
+
static void usb_msd_copy_data(MSDState *s, USBPacket *p)
{
uint32_t len;
@@ -227,7 +244,11 @@ 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));
+ if ((s->mode == USB_MSDM_DATAOUT) != (req->cmd.mode == SCSI_XFER_TO_DEV)) {
+ usb_msd_fatal_error(s);
+ return;
+ }
+
s->scsi_len = len;
s->scsi_off = 0;
if (p) {
@@ -317,6 +338,8 @@ void usb_msd_handle_reset(USBDevice *dev)
memset(&s->csw, 0, sizeof(s->csw));
s->mode = USB_MSDM_CBW;
+
+ s->needs_reset = false;
}
static void usb_msd_handle_control(USBDevice *dev, USBPacket *p,
@@ -382,6 +405,11 @@ static void usb_msd_handle_data(USBDevice *dev, USBPacket *p)
SCSIDevice *scsi_dev;
uint32_t len;
+ if (s->needs_reset) {
+ p->status = USB_RET_STALL;
+ return;
+ }
+
switch (p->pid) {
case USB_TOKEN_OUT:
if (devep != 2)
diff --git a/hw/usb/trace-events b/hw/usb/trace-events
index 914ca71..b652698 100644
--- a/hw/usb/trace-events
+++ b/hw/usb/trace-events
@@ -263,6 +263,7 @@ usb_msd_packet_complete(void) ""
usb_msd_cmd_submit(unsigned lun, unsigned tag, unsigned flags, unsigned len, unsigned data_len) "lun %u, tag 0x%x, flags 0x%08x, len %d, data-len %d"
usb_msd_cmd_complete(unsigned status, unsigned tag) "status %d, tag 0x%x"
usb_msd_cmd_cancel(unsigned tag) "tag 0x%x"
+usb_msd_fatal_error(void) ""
# dev-uas.c
usb_uas_reset(int addr) "dev %d"