qemu: Fix crash on failed VM startup

If VM startup fails early enough (can't find a referenced USB device),
libvirtd will crash trying to clear the VNC port bit, since port = 0,
which overflows us out of the bitmap bounds.

Fix this by being more defensive in the bitmap operations, and only
clearing a previously set VNC port.

Signed-off-by: Cole Robinson <crobinso@redhat.com>
This commit is contained in:
Cole Robinson 2010-06-01 15:10:19 -04:00
parent 08fee18cc2
commit 58406dd54e
2 changed files with 2 additions and 2 deletions

View File

@ -3773,7 +3773,7 @@ retry:
if ((vm->def->ngraphics == 1) &&
vm->def->graphics[0]->type == VIR_DOMAIN_GRAPHICS_TYPE_VNC &&
vm->def->graphics[0]->data.vnc.autoport &&
vm->def->graphics[0]->data.vnc.port != -1) {
vm->def->graphics[0]->data.vnc.port >= QEMU_VNC_PORT_MIN) {
if (virBitmapClearBit(driver->reservedVNCPorts,
vm->def->graphics[0]->data.vnc.port - \
QEMU_VNC_PORT_MIN) < 0) {

View File

@ -119,7 +119,7 @@ int virBitmapSetBit(virBitmapPtr bitmap, size_t b)
*/
int virBitmapClearBit(virBitmapPtr bitmap, size_t b)
{
if (b > bitmap->size - 1)
if (bitmap->size != 0 && b > bitmap->size - 1)
return -1;
bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] &= ~(1 << VIR_BITMAP_BIT_OFFSET(b));