[libvirt] [PATCH] _virtualboxCreateMachine: Avoid unbound stack
If the stars are in the right position and you're building with
VBox >= 4.2.0 it will happen that compiler thinks an array
allocated on the stack may be unbound:
In file included from vbox/vbox_V4_2.c:13:0:
vbox/vbox_tmpl.c: In function '_virtualboxCreateMachine':
vbox/vbox_tmpl.c:2811:1: error: stack usage might be unbounded [-Werror=stack-usage=]
_virtualboxCreateMachine(vboxGlobalData *data, virDomainDefPtr def, IMachine **machine,
char *uuidstr ATTRIBUTE_UNUSED)
^
Well, given how the variable is declared, I had some hard time
seeing it is actually bounded. Surprisingly compiler does not
complain because of -Wframe-larger-than. This is because
variable length arrays do not count into that warning.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/vbox/vbox_tmpl.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/src/vbox/vbox_tmpl.c b/src/vbox/vbox_tmpl.c
index 0fbd5b3..7a8205d 100644
--- a/src/vbox/vbox_tmpl.c
+++ b/src/vbox/vbox_tmpl.c
@@ -2812,7 +2812,7 @@ _virtualboxCreateMachine(vboxGlobalData *data, virDomainDefPtr def,
IMachine **m
{
vboxIID iid = VBOX_IID_INITIALIZER;
PRUnichar *machineNameUtf16 = NULL;
- nsresult rc;
+ nsresult rc = -1;
VBOX_UTF8_TO_UTF16(def->name, &machineNameUtf16);
vboxIIDFromUUID(&iid, def->uuid);
@@ -2843,18 +2843,12 @@ _virtualboxCreateMachine(vboxGlobalData *data, virDomainDefPtr
def, IMachine **m
override,
machine);
#else /* VBOX_API_VERSION >= 4002000 */
- const char *flagsUUIDPrefix = "UUID=";
- const char *flagsForceOverwrite = "forceOverwrite=0";
- const char *flagsSeparator = ",";
- char createFlags[strlen(flagsUUIDPrefix) + VIR_UUID_STRING_BUFLEN +
strlen(flagsSeparator) + strlen(flagsForceOverwrite) + 1];
+ char *createFlags = NULL;
PRUnichar *createFlagsUtf16 = NULL;
- snprintf(createFlags, sizeof(createFlags), "%s%s%s%s",
- flagsUUIDPrefix,
- uuidstr,
- flagsSeparator,
- flagsForceOverwrite
- );
+ if (virAsprintf(&createFlags,
+ "UUID=%s,forceOverwrite=0", uuidstr) < 0)
+ goto cleanup;
VBOX_UTF8_TO_UTF16(createFlags, &createFlagsUtf16);
rc = data->vboxObj->vtbl->CreateMachine(data->vboxObj,
NULL,
@@ -2864,6 +2858,8 @@ _virtualboxCreateMachine(vboxGlobalData *data, virDomainDefPtr def,
IMachine **m
nsnull,
createFlagsUtf16,
machine);
+ cleanup:
+ VIR_FREE(createFlags);
#endif /* VBOX_API_VERSION >= 4002000 */
}
VBOX_UTF16_FREE(machineNameUtf16);
--
2.4.10