From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
The qdev id of a device can be huge if it's on the end of a chain
of bridges; in reality such chains shouldn't occur but they can
be made to by chaining PCIe bridges together.
The migration format has a number of 256 character long format
limits; check we don't hit them (we already use pstrcat/cpy but
that just protects us from buffer overruns, we fairly quickly
hit an assert).
Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
Reviewed-by: Juan Quintela <quint...@redhat.com>
Message-Id: <20170202125956.21942-3-dgilb...@redhat.com>
Signed-off-by: Juan Quintela <quint...@redhat.com>
---
include/migration/vmstate.h | 2 ++
migration/savevm.c | 21 ++++++++++++++++-----
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index c38b00a..6233fe2 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -985,12 +985,14 @@ void vmstate_save_state(QEMUFile *f, const
VMStateDescription *vmsd,
bool vmstate_save_needed(const VMStateDescription *vmsd, void *opaque);
+/* Returns: 0 on success, -1 on failure */
int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
const VMStateDescription *vmsd,
void *base, int alias_id,
int required_for_version,
Error **errp);
+/* Returns: 0 on success, -1 on failure */
static inline int vmstate_register(DeviceState *dev, int instance_id,
const VMStateDescription *vmsd,
void *opaque)
diff --git a/migration/savevm.c b/migration/savevm.c
index b11b4a2..8b8c74d 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -590,8 +590,14 @@ int register_savevm_live(DeviceState *dev,
if (dev) {
char *id = qdev_get_dev_path(dev);
if (id) {
- pstrcpy(se->idstr, sizeof(se->idstr), id);
- pstrcat(se->idstr, sizeof(se->idstr), "/");
+ if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >=
+ sizeof(se->idstr)) {
+ error_report("Path too long for VMState (%s)", id);
+ g_free(id);
+ g_free(se);
+
+ return -1;
+ }
g_free(id);
se->compat = g_new0(CompatEntry, 1);
@@ -674,9 +680,14 @@ int vmstate_register_with_alias_id(DeviceState *dev, int
instance_id,
if (dev) {
char *id = qdev_get_dev_path(dev);
if (id) {
- pstrcpy(se->idstr, sizeof(se->idstr), id);
- pstrcat(se->idstr, sizeof(se->idstr), "/");
- g_free(id);
+ if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >=
+ sizeof(se->idstr)) {
+ error_setg(errp, "Path too long for VMState (%s)", id);
+ g_free(id);
+ g_free(se);
+
+ return -1;
+ }
se->compat = g_new0(CompatEntry, 1);
pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);
--
2.7.4
