thebeanogamer / rpms / qemu-kvm

Forked from rpms/qemu-kvm 5 months ago
Clone
80b7ec
From 9330e486e884f1757d6920a25c6cc491eedad0d0 Mon Sep 17 00:00:00 2001
80b7ec
From: Jon Maloy <jmaloy@redhat.com>
80b7ec
Date: Fri, 4 Sep 2020 16:09:13 -0400
80b7ec
Subject: [PATCH 3/3] usb: fix setup_len init (CVE-2020-14364)
80b7ec
80b7ec
RH-Author: Jon Maloy <jmaloy@redhat.com>
80b7ec
Message-id: <20200904160913.87759-3-jmaloy@redhat.com>
80b7ec
Patchwork-id: 98291
80b7ec
O-Subject: [RHEL-7.9 qemu-kvm PATCH 2/2] usb: fix setup_len init (CVE-2020-14364)
80b7ec
Bugzilla: 1869693
80b7ec
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
80b7ec
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
80b7ec
RH-Acked-by: Thomas Huth <thuth@redhat.com>
80b7ec
80b7ec
From: Gerd Hoffmann <kraxel@redhat.com>
80b7ec
80b7ec
Store calculated setup_len in a local variable, verify it, and only
80b7ec
write it to the struct (USBDevice->setup_len) in case it passed the
80b7ec
sanity checks.
80b7ec
80b7ec
This prevents other code (do_token_{in,out} functions specifically)
80b7ec
from working with invalid USBDevice->setup_len values and overrunning
80b7ec
the USBDevice->setup_buf[] buffer.
80b7ec
80b7ec
Fixes: CVE-2020-14364
80b7ec
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
80b7ec
Tested-by: Gonglei <arei.gonglei@huawei.com>
80b7ec
Reviewed-by: Li Qiang <liq3ea@gmail.com>
80b7ec
Message-id: 20200825053636.29648-1-kraxel@redhat.com
80b7ec
(cherry picked from commit b946434f2659a182afc17e155be6791ebfb302eb)
80b7ec
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
80b7ec
Signed-off-by: Jon Maloy <jmaloy.redhat.com>
80b7ec
---
80b7ec
 hw/usb/core.c | 16 ++++++++++------
80b7ec
 1 file changed, 10 insertions(+), 6 deletions(-)
80b7ec
80b7ec
diff --git a/hw/usb/core.c b/hw/usb/core.c
80b7ec
index f0201e30b4..f0038e44ae 100644
80b7ec
--- a/hw/usb/core.c
80b7ec
+++ b/hw/usb/core.c
80b7ec
@@ -121,6 +121,7 @@ void usb_wakeup(USBEndpoint *ep, unsigned int stream)
80b7ec
 static void do_token_setup(USBDevice *s, USBPacket *p)
80b7ec
 {
80b7ec
     int request, value, index;
80b7ec
+    unsigned int setup_len;
80b7ec
 
80b7ec
     if (p->iov.size != 8) {
80b7ec
         p->status = USB_RET_STALL;
80b7ec
@@ -130,14 +131,15 @@ static void do_token_setup(USBDevice *s, USBPacket *p)
80b7ec
     usb_packet_copy(p, s->setup_buf, p->iov.size);
80b7ec
     s->setup_index = 0;
80b7ec
     p->actual_length = 0;
80b7ec
-    s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];
80b7ec
-    if (s->setup_len > sizeof(s->data_buf)) {
80b7ec
+    setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
80b7ec
+    if (setup_len > sizeof(s->data_buf)) {
80b7ec
         fprintf(stderr,
80b7ec
                 "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
80b7ec
-                s->setup_len, sizeof(s->data_buf));
80b7ec
+                setup_len, sizeof(s->data_buf));
80b7ec
         p->status = USB_RET_STALL;
80b7ec
         return;
80b7ec
     }
80b7ec
+    s->setup_len = setup_len;
80b7ec
 
80b7ec
     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
80b7ec
     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
80b7ec
@@ -251,26 +253,28 @@ static void do_token_out(USBDevice *s, USBPacket *p)
80b7ec
 static void do_parameter(USBDevice *s, USBPacket *p)
80b7ec
 {
80b7ec
     int i, request, value, index;
80b7ec
+    unsigned int setup_len;
80b7ec
 
80b7ec
     for (i = 0; i < 8; i++) {
80b7ec
         s->setup_buf[i] = p->parameter >> (i*8);
80b7ec
     }
80b7ec
 
80b7ec
     s->setup_state = SETUP_STATE_PARAM;
80b7ec
-    s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];
80b7ec
     s->setup_index = 0;
80b7ec
 
80b7ec
     request = (s->setup_buf[0] << 8) | s->setup_buf[1];
80b7ec
     value   = (s->setup_buf[3] << 8) | s->setup_buf[2];
80b7ec
     index   = (s->setup_buf[5] << 8) | s->setup_buf[4];
80b7ec
 
80b7ec
-    if (s->setup_len > sizeof(s->data_buf)) {
80b7ec
+    setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
80b7ec
+    if (setup_len > sizeof(s->data_buf)) {
80b7ec
         fprintf(stderr,
80b7ec
                 "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
80b7ec
-                s->setup_len, sizeof(s->data_buf));
80b7ec
+                setup_len, sizeof(s->data_buf));
80b7ec
         p->status = USB_RET_STALL;
80b7ec
         return;
80b7ec
     }
80b7ec
+    s->setup_len = setup_len;
80b7ec
 
80b7ec
     if (p->pid == USB_TOKEN_OUT) {
80b7ec
         usb_packet_copy(p, s->data_buf, s->setup_len);
80b7ec
-- 
80b7ec
2.18.2
80b7ec