Patchwork [v5,10/24] hw/pci/pcie_aer.c: fix buffer overruns on invalid state load

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Submitter Michael S. Tsirkin
Date April 3, 2014, 4:51 p.m.
Message ID <1396543778-22307-11-git-send-email-mst@redhat.com>
Download mbox | patch
Permalink /patch/336669/
State New
Headers show

Comments

Michael S. Tsirkin - April 3, 2014, 4:51 p.m.
4) CVE-2013-4529
hw/pci/pcie_aer.c    pcie aer log can overrun the buffer if log_num is
                     too large

There are two issues in this file:
1. log_max from remote can be larger than on local
then buffer will overrun with data coming from state file.
2. log_num can be larger then we get data corruption
again with an overflow but not adversary controlled.

Fix both issues.

Reported-by: Anthony Liguori <anthony@codemonkey.ws>
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/pci/pcie_aer.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

Patch

diff --git a/hw/pci/pcie_aer.c b/hw/pci/pcie_aer.c
index 991502e..535be2c 100644
--- a/hw/pci/pcie_aer.c
+++ b/hw/pci/pcie_aer.c
@@ -795,6 +795,13 @@  static const VMStateDescription vmstate_pcie_aer_err = {
     }
 };
 
+static bool pcie_aer_state_log_num_valid(void *opaque, int version_id)
+{
+    PCIEAERLog *s = opaque;
+
+    return s->log_num <= s->log_max;
+}
+
 const VMStateDescription vmstate_pcie_aer_log = {
     .name = "PCIE_AER_ERROR_LOG",
     .version_id = 1,
@@ -802,7 +809,8 @@  const VMStateDescription vmstate_pcie_aer_log = {
     .minimum_version_id_old = 1,
     .fields     = (VMStateField[]) {
         VMSTATE_UINT16(log_num, PCIEAERLog),
-        VMSTATE_UINT16(log_max, PCIEAERLog),
+        VMSTATE_UINT16_EQUAL(log_max, PCIEAERLog),
+        VMSTATE_VALIDATE("log_num <= log_max", pcie_aer_state_log_num_valid),
         VMSTATE_STRUCT_VARRAY_POINTER_UINT16(log, PCIEAERLog, log_num,
                               vmstate_pcie_aer_err, PCIEAERErr),
         VMSTATE_END_OF_LIST()