From 225777a1435ad6cdbbee99270d2b120cdf736bcb Mon Sep 17 00:00:00 2001
Message-Id: <225777a1435ad6cdbbee99270d2b120cdf736bcb@dist-git>
From: Peter Krempa <pkrempa@redhat.com>
Date: Wed, 17 Sep 2014 23:17:23 +0200
Subject: [PATCH] CVE-2014-3633: qemu: blkiotune: Use correct definition when
 looking up disk

Live definition was used to look up the disk index while persistent one
was indexed leading to a crash in qemuDomainGetBlockIoTune. Use the
correct def and report a nice error.

Unfortunately it's accessible via read-only connection, though it can
only crash libvirtd in the cases where the guest is hot-plugging disks
without reflecting those changes to the persistent definition.  So
avoiding hotplug, or doing hotplug where persistent is always modified
alongside live definition, will avoid the out-of-bounds access.

Introduced in: eca96694a7f992be633d48d5ca03cedc9bbc3c9aa (v0.9.8)
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1140724
Reported-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>

(cherry picked from commit 3e745e8f775dfe6f64f18b5c2fe4791b35d3546b)
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/qemu/qemu_driver.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 48bf612..63bb629 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -16069,9 +16069,13 @@ qemuDomainGetBlockIoTune(virDomainPtr dom,
     }
 
     if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
-        int idx = virDomainDiskIndexByName(vm->def, disk, true);
-        if (idx < 0)
+        int idx = virDomainDiskIndexByName(persistentDef, disk, true);
+        if (idx < 0) {
+            virReportError(VIR_ERR_INVALID_ARG,
+                           _("disk '%s' was not found in the domain config"),
+                           disk);
             goto endjob;
+        }
         reply = persistentDef->disks[idx]->blkdeviotune;
     }
 
-- 
2.1.0