Merge remote-tracking branch 'remotes/kraxel/tags/usb-20210505-pull-request' into staging

usb: fix some memory allocation issues (CVE-2021-3527).
usb: add stubs, allow building without usb subsystem.

# gpg: Signature made Wed 05 May 2021 14:07:02 BST
# gpg:                using RSA key A0328CFFB93A17A79901FE7D4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/usb-20210505-pull-request:
  usb: limit combined packets to 1 MiB (CVE-2021-3527)
  usb/mtp: avoid dynamic stack allocation
  usb/redir: avoid dynamic stack allocation (CVE-2021-3527)
  usb/hid: avoid dynamic stack allocation
  hw/usb: Do not build USB subsystem if not required
  hw/usb/host-stub: Remove unused header

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

7 files changed, 13 insertions, 14 deletions

diff --git a/hw/usb/combined-packet.c b/hw/usb/combined-packet.c
index 5d57e88..e56802f 100644
--- a/hw/usb/combined-packet.c
+++ b/hw/usb/combined-packet.c
@@ -171,7 +171,9 @@ void usb_ep_combine_input_packets(USBEndpoint *ep)
         if ((p->iov.size % ep->max_packet_size) != 0 || !p->short_not_ok ||
                 next == NULL ||
                 /* Work around for Linux usbfs bulk splitting + migration */
-                (totalsize == (16 * KiB - 36) && p->int_req)) {
+                (totalsize == (16 * KiB - 36) && p->int_req) ||
+                /* Next package may grow combined package over 1MiB */
+                totalsize > 1 * MiB - ep->max_packet_size) {
             usb_device_handle_data(ep->dev, first);
             assert(first->status == USB_RET_ASYNC);
             if (first->combined) {
diff --git a/hw/usb/dev-hid.c b/hw/usb/dev-hid.c
index fc39bab..1c7ae97 100644
--- a/hw/usb/dev-hid.c
+++ b/hw/usb/dev-hid.c
@@ -656,7 +656,7 @@ static void usb_hid_handle_data(USBDevice *dev, USBPacket *p)
 {
     USBHIDState *us = USB_HID(dev);
     HIDState *hs = &us->hid;
-    uint8_t buf[p->iov.size];
+    g_autofree uint8_t *buf = g_malloc(p->iov.size);
     int len = 0;
 
     switch (p->pid) {
diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index bbb8274..2a895a7 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -907,7 +907,8 @@ static MTPData *usb_mtp_get_object_handles(MTPState *s, MTPControl *c,
                                            MTPObject *o)
 {
     MTPData *d = usb_mtp_data_alloc(c);
-    uint32_t i = 0, handles[o->nchildren];
+    uint32_t i = 0;
+    g_autofree uint32_t *handles = g_new(uint32_t, o->nchildren);
     MTPObject *iter;
 
     trace_usb_mtp_op_get_object_handles(s->dev.addr, o->handle, o->path);
diff --git a/hw/usb/dev-wacom.c b/hw/usb/dev-wacom.c
index b595048..ed687bc 100644
--- a/hw/usb/dev-wacom.c
+++ b/hw/usb/dev-wacom.c
@@ -301,7 +301,7 @@ static void usb_wacom_handle_control(USBDevice *dev, USBPacket *p,
 static void usb_wacom_handle_data(USBDevice *dev, USBPacket *p)
 {
     USBWacomState *s = (USBWacomState *) dev;
-    uint8_t buf[p->iov.size];
+    g_autofree uint8_t *buf = g_malloc(p->iov.size);
     int len = 0;
 
     switch (p->pid) {
diff --git a/hw/usb/host-stub.c b/hw/usb/host-stub.c
index 538ed29..80809ce 100644
--- a/hw/usb/host-stub.c
+++ b/hw/usb/host-stub.c
@@ -31,7 +31,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "ui/console.h"
 #include "hw/usb.h"
 #include "monitor/monitor.h"
 
diff --git a/hw/usb/meson.build b/hw/usb/meson.build
index fb7a74e..f357270 100644
--- a/hw/usb/meson.build
+++ b/hw/usb/meson.build
@@ -1,17 +1,14 @@
 hw_usb_modules = {}
 
 # usb subsystem core
-softmmu_ss.add(files(
+softmmu_ss.add(when: 'CONFIG_USB', if_true: files(
   'bus.c',
   'combined-packet.c',
   'core.c',
-  'pcap.c',
-  'libhw.c'
-))
-
-softmmu_ss.add(when: 'CONFIG_USB', if_true: files(
   'desc.c',
   'desc-msos.c',
+  'libhw.c',
+  'pcap.c',
 ))
 
 # usb host adapters
diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index 17f06f3..6a75b0d 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -620,7 +620,7 @@ static void usbredir_handle_iso_data(USBRedirDevice *dev, USBPacket *p,
                 .endpoint = ep,
                 .length = p->iov.size
             };
-            uint8_t buf[p->iov.size];
+            g_autofree uint8_t *buf = g_malloc(p->iov.size);
             /* No id, we look at the ep when receiving a status back */
             usb_packet_copy(p, buf, p->iov.size);
             usbredirparser_send_iso_packet(dev->parser, 0, &iso_packet,
@@ -818,7 +818,7 @@ static void usbredir_handle_bulk_data(USBRedirDevice *dev, USBPacket *p,
         usbredirparser_send_bulk_packet(dev->parser, p->id,
                                         &bulk_packet, NULL, 0);
     } else {
-        uint8_t buf[size];
+        g_autofree uint8_t *buf = g_malloc(size);
         usb_packet_copy(p, buf, size);
         usbredir_log_data(dev, "bulk data out:", buf, size);
         usbredirparser_send_bulk_packet(dev->parser, p->id,
@@ -923,7 +923,7 @@ static void usbredir_handle_interrupt_out_data(USBRedirDevice *dev,
                                                USBPacket *p, uint8_t ep)
 {
     struct usb_redir_interrupt_packet_header interrupt_packet;
-    uint8_t buf[p->iov.size];
+    g_autofree uint8_t *buf = g_malloc(p->iov.size);
 
     DPRINTF("interrupt-out ep %02X len %zd id %"PRIu64"\n", ep,
             p->iov.size, p->id);