|
 |
9ae3a8 |
From ba24567fd90702ea40ff320a79bc921b38510f22 Mon Sep 17 00:00:00 2001
|
|
|
9ae3a8 |
From: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
9ae3a8 |
Date: Thu, 21 Jan 2016 07:17:43 +0100
|
|
|
9ae3a8 |
Subject: [PATCH 2/2] fw_cfg: add check to validate current entry value
|
|
|
9ae3a8 |
(CVE-2016-1714)
|
|
|
9ae3a8 |
MIME-Version: 1.0
|
|
|
9ae3a8 |
Content-Type: text/plain; charset=UTF-8
|
|
|
9ae3a8 |
Content-Transfer-Encoding: 8bit
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
RH-Author: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
9ae3a8 |
Message-id: <1453360663-5066-1-git-send-email-mrezanin@redhat.com>
|
|
|
9ae3a8 |
Patchwork-id: 68834
|
|
|
9ae3a8 |
O-Subject: [RHEL-7.2.z/RHEL-7.3 qemu-kvm PATCH] fw_cfg: add check to validate current entry value (CVE-2016-1714)
|
|
|
9ae3a8 |
Bugzilla: 1298048
|
|
|
9ae3a8 |
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
|
|
|
9ae3a8 |
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
|
|
|
9ae3a8 |
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
From: Prasad J Pandit <pjp@fedoraproject.org>
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
When processing firmware configurations, an OOB r/w access occurs
|
|
|
9ae3a8 |
if 's->cur_entry' is set to be invalid(FW_CFG_INVALID=0xffff).
|
|
|
9ae3a8 |
Add a check to validate 's->cur_entry' to avoid such access.
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
This patch is based on upstream commit 66f8fd9dda312191b78d2a2ba2848bcee76127a2
|
|
|
9ae3a8 |
Author: Gabriel L. Somlo <somlo@cmu.edu>
|
|
|
9ae3a8 |
Date: Thu Nov 5 09:32:50 2015 -0500
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
fw_cfg: avoid calculating invalid current entry pointer
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
When calculating a pointer to the currently selected fw_cfg item, the
|
|
|
9ae3a8 |
following is used:
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
FWCfgEntry *e = &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
When s->cur_entry is FW_CFG_INVALID, we are calculating the address of
|
|
|
9ae3a8 |
a non-existent element in s->entries[arch][...], which is undefined.
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
This patch ensures the resulting entry pointer is set to NULL whenever
|
|
|
9ae3a8 |
s->cur_entry is FW_CFG_INVALID.
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
Reported-by: Laszlo Ersek <lersek@redhat.com>
|
|
|
9ae3a8 |
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
|
|
|
9ae3a8 |
Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
|
|
|
9ae3a8 |
Message-id: 1446733972-1602-5-git-send-email-somlo@cmu.edu
|
|
|
9ae3a8 |
Cc: Marc Marí <markmb@redhat.com>
|
|
|
9ae3a8 |
Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
|
|
|
9ae3a8 |
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
|
|
|
9ae3a8 |
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
with added chunk for fw_cfg_write() that was removed in commit
|
|
|
9ae3a8 |
023e3148567ac898c7258138f8e86c3c2bb40d07
|
|
|
9ae3a8 |
and missing chunk for fw_cfg_dma_transfer that was added in commit
|
|
|
9ae3a8 |
a4c0d1deb785611c96a455f65ec032976b00b36f.
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
Reported-by: Donghai Zdh <donghai.zdh@alibaba-inc.com>
|
|
|
9ae3a8 |
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
|
|
|
9ae3a8 |
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
9ae3a8 |
---
|
|
|
9ae3a8 |
hw/nvram/fw_cfg.c | 12 ++++++++----
|
|
|
9ae3a8 |
1 file changed, 8 insertions(+), 4 deletions(-)
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
|
|
|
9ae3a8 |
index b865c09..fcb3146 100644
|
|
|
9ae3a8 |
--- a/hw/nvram/fw_cfg.c
|
|
|
9ae3a8 |
+++ b/hw/nvram/fw_cfg.c
|
|
|
9ae3a8 |
@@ -207,12 +207,15 @@ static void fw_cfg_reboot(FWCfgState *s)
|
|
|
9ae3a8 |
static void fw_cfg_write(FWCfgState *s, uint8_t value)
|
|
|
9ae3a8 |
{
|
|
|
9ae3a8 |
int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL);
|
|
|
9ae3a8 |
- FWCfgEntry *e = &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
|
|
|
9ae3a8 |
+ FWCfgEntry *e = (s->cur_entry == FW_CFG_INVALID) ? NULL :
|
|
|
9ae3a8 |
+ &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
trace_fw_cfg_write(s, value);
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
- if (s->cur_entry & FW_CFG_WRITE_CHANNEL && e->callback &&
|
|
|
9ae3a8 |
- s->cur_offset < e->len) {
|
|
|
9ae3a8 |
+ if (s->cur_entry & FW_CFG_WRITE_CHANNEL
|
|
|
9ae3a8 |
+ && e != NULL
|
|
|
9ae3a8 |
+ && e->callback
|
|
|
9ae3a8 |
+ && s->cur_offset < e->len) {
|
|
|
9ae3a8 |
e->data[s->cur_offset++] = value;
|
|
|
9ae3a8 |
if (s->cur_offset == e->len) {
|
|
|
9ae3a8 |
e->callback(e->callback_opaque, e->data);
|
|
|
9ae3a8 |
@@ -241,7 +244,8 @@ static int fw_cfg_select(FWCfgState *s, uint16_t key)
|
|
|
9ae3a8 |
static uint8_t fw_cfg_read(FWCfgState *s)
|
|
|
9ae3a8 |
{
|
|
|
9ae3a8 |
int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL);
|
|
|
9ae3a8 |
- FWCfgEntry *e = &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
|
|
|
9ae3a8 |
+ FWCfgEntry *e = (s->cur_entry == FW_CFG_INVALID) ? NULL :
|
|
|
9ae3a8 |
+ &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK];
|
|
|
9ae3a8 |
uint8_t ret;
|
|
|
9ae3a8 |
|
|
|
9ae3a8 |
if (s->cur_entry == FW_CFG_INVALID || !e->data || s->cur_offset >= e->len)
|
|
|
9ae3a8 |
--
|
|
|
9ae3a8 |
1.8.3.1
|
|
|
9ae3a8 |
|