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[Qemu-devel] [PATCH 18/36] virtio-scsi: fix buffer overrun on invalid st
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PATCH 18/36] virtio-scsi: fix buffer overrun on invalid state load |
Date: |
Mon, 5 May 2014 22:30:16 +0200 |
From: "Michael S. Tsirkin" <address@hidden>
CVE-2013-4542
hw/scsi/scsi-bus.c invokes load_request.
virtio_scsi_load_request does:
qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
this probably can make elem invalid, for example,
make in_num or out_num huge, then:
virtio_scsi_parse_req(s, vs->cmd_vqs[n], req);
will do:
if (req->elem.out_num > 1) {
qemu_sgl_init_external(req, &req->elem.out_sg[1],
&req->elem.out_addr[1],
req->elem.out_num - 1);
} else {
qemu_sgl_init_external(req, &req->elem.in_sg[1],
&req->elem.in_addr[1],
req->elem.in_num - 1);
}
and this will access out of array bounds.
Note: this adds security checks within assert calls since
SCSIBusInfo's load_request cannot fail.
For now simply disable builds with NDEBUG - there seems
to be little value in supporting these.
Cc: Andreas Färber <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
---
hw/scsi/virtio-scsi.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index b0d7517..1752193 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -147,6 +147,15 @@ static void *virtio_scsi_load_request(QEMUFile *f,
SCSIRequest *sreq)
qemu_get_be32s(f, &n);
assert(n < vs->conf.num_queues);
qemu_get_buffer(f, (unsigned char *)&req->elem, sizeof(req->elem));
+ /* TODO: add a way for SCSIBusInfo's load_request to fail,
+ * and fail migration instead of asserting here.
+ * When we do, we might be able to re-enable NDEBUG below.
+ */
+#ifdef NDEBUG
+#error building with NDEBUG is not supported
+#endif
+ assert(req->elem.in_num <= ARRAY_SIZE(req->elem.in_sg));
+ assert(req->elem.out_num <= ARRAY_SIZE(req->elem.out_sg));
virtio_scsi_parse_req(s, vs->cmd_vqs[n], req);
scsi_req_ref(sreq);
--
1.9.0
- [Qemu-devel] [PATCH 06/36] virtio: out-of-bounds buffer write on invalid state load, (continued)
- [Qemu-devel] [PATCH 06/36] virtio: out-of-bounds buffer write on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 08/36] hpet: fix buffer overrun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 09/36] hw/pci/pcie_aer.c: fix buffer overruns on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 10/36] pl022: fix buffer overun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 11/36] vmstate: fix buffer overflow in target-arm/machine.c, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 12/36] virtio: avoid buffer overrun on incoming migration, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 14/36] pxa2xx: avoid buffer overrun on incoming migration, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 13/36] virtio: validate num_sg when mapping, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 16/36] tsc210x: fix buffer overrun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 15/36] ssd0323: fix buffer overun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 18/36] virtio-scsi: fix buffer overrun on invalid state load,
Juan Quintela <=
- [Qemu-devel] [PATCH 17/36] zaurus: fix buffer overrun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 21/36] savevm: Ignore minimum_version_id_old if there is no load_state_old, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 22/36] ssi-sd: fix buffer overrun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 19/36] vmstate: s/VMSTATE_INT32_LE/VMSTATE_INT32_POSITIVE_LE/, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 23/36] openpic: avoid buffer overrun on incoming migration, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 20/36] usb: sanity check setup_index+setup_len in post_load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 24/36] virtio-net: out-of-bounds buffer write on load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 27/36] Make qemu_peek_buffer loop until it gets it's data, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 26/36] Disallow outward migration while awaiting incoming migration, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 25/36] virtio: validate config_len on load, Juan Quintela, 2014/05/05