[PATCH] qemu: fix CVE-2020-14364

* [PATCH] qemu: fix CVE-2020-14364
@ 2020-09-10 20:01 Sakib Sajal
  2020-09-10 21:03 ` [OE-core] " Ross Burton
  0 siblings, 1 reply; 2+ messages in thread
From: Sakib Sajal @ 2020-09-10 20:01 UTC (permalink / raw)
  To: openembedded-core; +Cc: Sakib Sajal

Upstream-Status: Backport [b946434f2659a182afc17e155be6791ebfb302eb]

Signed-off-by: Sakib Sajal <sakib.sajal@windriver.com>
---
 meta/recipes-devtools/qemu/qemu.inc           |  1 +
 ...sb-fix-setup_len-init-CVE-2020-14364.patch | 88 +++++++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100644 meta/recipes-devtools/qemu/qemu/0001-usb-fix-setup_len-init-CVE-2020-14364.patch

diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
index 5599382a92..0d296089d0 100644
--- a/meta/recipes-devtools/qemu/qemu.inc
+++ b/meta/recipes-devtools/qemu/qemu.inc
@@ -30,6 +30,7 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
            file://0001-Add-enable-disable-udev.patch \
 	   file://0001-qemu-Do-not-include-file-if-not-exists.patch \
 	   file://find_datadir.patch \
+	   file://0001-usb-fix-setup_len-init-CVE-2020-14364.patch \
 	   "
 UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+(\.\d+)+)\.tar"
 
diff --git a/meta/recipes-devtools/qemu/qemu/0001-usb-fix-setup_len-init-CVE-2020-14364.patch b/meta/recipes-devtools/qemu/qemu/0001-usb-fix-setup_len-init-CVE-2020-14364.patch
new file mode 100644
index 0000000000..3915d2511f
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/0001-usb-fix-setup_len-init-CVE-2020-14364.patch
@@ -0,0 +1,88 @@
+From b946434f2659a182afc17e155be6791ebfb302eb Mon Sep 17 00:00:00 2001
+From: Gerd Hoffmann <kraxel@redhat.com>
+Date: Tue, 25 Aug 2020 07:36:36 +0200
+Subject: [PATCH] usb: fix setup_len init (CVE-2020-14364)
+
+Store calculated setup_len in a local variable, verify it, and only
+write it to the struct (USBDevice->setup_len) in case it passed the
+sanity checks.
+
+This prevents other code (do_token_{in,out} functions specifically)
+from working with invalid USBDevice->setup_len values and overrunning
+the USBDevice->setup_buf[] buffer.
+
+Fixes: CVE-2020-14364
+Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
+Tested-by: Gonglei <arei.gonglei@huawei.com>
+Reviewed-by: Li Qiang <liq3ea@gmail.com>
+Message-id: 20200825053636.29648-1-kraxel@redhat.com
+---
+ hw/usb/core.c | 16 ++++++++++------
+ 1 file changed, 10 insertions(+), 6 deletions(-)
+
+diff --git a/hw/usb/core.c b/hw/usb/core.c
+index 5abd128b6b..5234dcc73f 100644
+--- a/hw/usb/core.c
++++ b/hw/usb/core.c
+@@ -129,6 +129,7 @@ void usb_wakeup(USBEndpoint *ep, unsigned int stream)
+ static void do_token_setup(USBDevice *s, USBPacket *p)
+ {
+     int request, value, index;
++    unsigned int setup_len;
+ 
+     if (p->iov.size != 8) {
+         p->status = USB_RET_STALL;
+@@ -138,14 +139,15 @@ static void do_token_setup(USBDevice *s, USBPacket *p)
+     usb_packet_copy(p, s->setup_buf, p->iov.size);
+     s->setup_index = 0;
+     p->actual_length = 0;
+-    s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];
+-    if (s->setup_len > sizeof(s->data_buf)) {
++    setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
++    if (setup_len > sizeof(s->data_buf)) {
+         fprintf(stderr,
+                 "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
+-                s->setup_len, sizeof(s->data_buf));
++                setup_len, sizeof(s->data_buf));
+         p->status = USB_RET_STALL;
+         return;
+     }
++    s->setup_len = setup_len;
+ 
+     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
+     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
+@@ -259,26 +261,28 @@ static void do_token_out(USBDevice *s, USBPacket *p)
+ static void do_parameter(USBDevice *s, USBPacket *p)
+ {
+     int i, request, value, index;
++    unsigned int setup_len;
+ 
+     for (i = 0; i < 8; i++) {
+         s->setup_buf[i] = p->parameter >> (i*8);
+     }
+ 
+     s->setup_state = SETUP_STATE_PARAM;
+-    s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];
+     s->setup_index = 0;
+ 
+     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
+     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
+     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
+ 
+-    if (s->setup_len > sizeof(s->data_buf)) {
++    setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
++    if (setup_len > sizeof(s->data_buf)) {
+         fprintf(stderr,
+                 "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
+-                s->setup_len, sizeof(s->data_buf));
++                setup_len, sizeof(s->data_buf));
+         p->status = USB_RET_STALL;
+         return;
+     }
++    s->setup_len = setup_len;
+ 
+     if (p->pid == USB_TOKEN_OUT) {
+         usb_packet_copy(p, s->data_buf, s->setup_len);
+-- 
+2.20.1
+
-- 
2.27.0


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