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Re: [Qemu-devel] [PATCH 07/23] hw/pci/pcie_aer.c: fix buffer overruns on
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH 07/23] hw/pci/pcie_aer.c: fix buffer overruns on invalid state load |
Date: |
Wed, 4 Dec 2013 10:40:04 +0200 |
On Tue, Dec 03, 2013 at 08:59:52PM +0000, Peter Maydell wrote:
> On 3 December 2013 20:41, Michael S. Tsirkin <address@hidden> wrote:
> > On Tue, Dec 03, 2013 at 06:30:46PM +0000, Peter Maydell wrote:
> >> On 3 December 2013 16:28, Michael S. Tsirkin <address@hidden> wrote:
> >> > const VMStateDescription vmstate_pcie_aer_log = {
> >> > .name = "PCIE_AER_ERROR_LOG",
> >> > .version_id = 1,
> >> > .minimum_version_id = 1,
> >> > .minimum_version_id_old = 1,
> >> > + .post_load = pcie_aer_state_post_load,
> >> > .fields = (VMStateField[]) {
> >> > VMSTATE_UINT16(log_num, PCIEAERLog),
> >> > - VMSTATE_UINT16(log_max, PCIEAERLog),
> >> > - VMSTATE_STRUCT_VARRAY_POINTER_UINT16(log, PCIEAERLog, log_num,
> >> > + VMSTATE_UINT16_EQUAL(log_max, PCIEAERLog),
> >> > + VMSTATE_STRUCT_VARRAY_POINTER_UINT16(log, PCIEAERLog, log_max,
> >> > vmstate_pcie_aer_err, PCIEAERErr),
> >> > VMSTATE_END_OF_LIST()
> >> > }
> >>
> >> Isn't this a migration compability break?
> >
> > How is it a break?
>
> If a QEMU with this patch sends data to a QEMU without it, then the
> receiving end will think it should expect log_num array entries but the
> sending end is going to send log_max of them. Conversely, an old->new
> migration is going to send fewer array entries than the destination
> expects. Or have I misinterpreted how the VARRAY entries work?
>
> thanks
> -- PMM
Ah, got it. You are right, good catch. I think we need VMSTATE_UINT16_LE, this
will
make sure log_num <= log_max without changing
VMSTATE_STRUCT_VARRAY size.
- [Qemu-devel] [PATCH 03/23] virtio-net: out-of-bounds buffer write on invalid state load, (continued)
[Qemu-devel] [PATCH 08/23] pl022: fix buffer overun on invalid state load, Michael S. Tsirkin, 2013/12/03
[Qemu-devel] [PATCH 09/23] target-arm/machine.c: fix buffer overflow on invalid state load, Michael S. Tsirkin, 2013/12/03
[Qemu-devel] [PATCH 10/23] stellaris_enet: avoid buffer overrun on incoming migration, Michael S. Tsirkin, 2013/12/03
[Qemu-devel] [PATCH 12/23] stellaris_enet: avoid buffer orerrun on incoming migration (part 3), Michael S. Tsirkin, 2013/12/03
[Qemu-devel] [PATCH 13/23] virtio: avoid buffer overrun on incoming migration, Michael S. Tsirkin, 2013/12/03
[Qemu-devel] [PATCH 14/23] openpic: avoid buffer overrun on incoming migration, Michael S. Tsirkin, 2013/12/03
[Qemu-devel] [PATCH 15/23] pxa2xx: avoid buffer overrun on incoming migration, Michael S. Tsirkin, 2013/12/03