[libvirt] [PATCH v2] qemu: Fix crash on failed VM startup
Cole Robinson
crobinso at redhat.com
Fri Jun 18 15:58:56 UTC 2010
On 06/18/2010 06:44 AM, Daniel P. Berrange wrote:
> On Wed, Jun 02, 2010 at 10:55:17AM -0400, Cole Robinson wrote:
>> 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.
>>
>> v2: Add safety check to all relevant bitmap ops.
>>
>> Signed-off-by: Cole Robinson <crobinso at redhat.com>
>> ---
>> src/qemu/qemu_driver.c | 2 +-
>> src/util/bitmap.c | 6 +++---
>> 2 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
>> index c8cd50a..f5a1310 100644
>> --- a/src/qemu/qemu_driver.c
>> +++ b/src/qemu/qemu_driver.c
>> @@ -3741,7 +3741,7 @@ 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) {
>> diff --git a/src/util/bitmap.c b/src/util/bitmap.c
>> index 69094a5..cef3fc4 100644
>> --- a/src/util/bitmap.c
>> +++ b/src/util/bitmap.c
>> @@ -100,7 +100,7 @@ void virBitmapFree(virBitmapPtr bitmap)
>> */
>> int virBitmapSetBit(virBitmapPtr bitmap, size_t b)
>> {
>> - if (b > bitmap->size - 1)
>> + if (bitmap->size <= b)
>> return -1;
>>
>> bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] |= (1 << VIR_BITMAP_BIT_OFFSET(b));
>> @@ -118,7 +118,7 @@ int virBitmapSetBit(virBitmapPtr bitmap, size_t b)
>> */
>> int virBitmapClearBit(virBitmapPtr bitmap, size_t b)
>> {
>> - if (b > bitmap->size - 1)
>> + if (bitmap->size <= b)
>> return -1;
>>
>> bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] &= ~(1 << VIR_BITMAP_BIT_OFFSET(b));
>> @@ -140,7 +140,7 @@ int virBitmapGetBit(virBitmapPtr bitmap, size_t b, bool *result)
>> {
>> uint32_t bit;
>>
>> - if (b > bitmap->size - 1)
>> + if (bitmap->size <= b)
>> return -1;
>>
>> bit = bitmap->map[VIR_BITMAP_UNIT_OFFSET(b)] &
>
> ACK, this patch doesn't seem to have ever been pushed - current GIT still
> crashes on abort of VM startup
>
> Daniel
Pushed now, accidentally in 2 commits though, since I pushed v1 first.
Thanks,
Cole
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