From 73d963c0a75cb99c6aaa3f6f25e427aa0b35a02e Mon Sep 17 00:00:00 2001 From: Michael Roth Date: Mon, 28 Apr 2014 16:08:17 +0300 Subject: [PATCH] openpic: avoid buffer overrun on incoming migration CVE-2013-4534 opp->nb_cpus is read from the wire and used to determine how many IRQDest elements to read into opp->dst[]. If the value exceeds the length of opp->dst[], MAX_CPU, opp->dst[] can be overrun with arbitrary data from the wire. Fix this by failing migration if the value read from the wire exceeds MAX_CPU. Signed-off-by: Michael Roth Reviewed-by: Alexander Graf Signed-off-by: Michael S. Tsirkin Signed-off-by: Juan Quintela --- hw/intc/openpic.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/hw/intc/openpic.c b/hw/intc/openpic.c index be76fbd78f..17136c9333 100644 --- a/hw/intc/openpic.c +++ b/hw/intc/openpic.c @@ -41,6 +41,7 @@ #include "hw/sysbus.h" #include "hw/pci/msi.h" #include "qemu/bitops.h" +#include "qapi/qmp/qerror.h" //#define DEBUG_OPENPIC @@ -1416,7 +1417,7 @@ static void openpic_load_IRQ_queue(QEMUFile* f, IRQQueue *q) static int openpic_load(QEMUFile* f, void *opaque, int version_id) { OpenPICState *opp = (OpenPICState *)opaque; - unsigned int i; + unsigned int i, nb_cpus; if (version_id != 1) { return -EINVAL; @@ -1428,7 +1429,11 @@ static int openpic_load(QEMUFile* f, void *opaque, int version_id) qemu_get_be32s(f, &opp->spve); qemu_get_be32s(f, &opp->tfrr); - qemu_get_be32s(f, &opp->nb_cpus); + qemu_get_be32s(f, &nb_cpus); + if (opp->nb_cpus != nb_cpus) { + return -EINVAL; + } + assert(nb_cpus > 0 && nb_cpus <= MAX_CPU); for (i = 0; i < opp->nb_cpus; i++) { qemu_get_sbe32s(f, &opp->dst[i].ctpr); @@ -1567,6 +1572,13 @@ static void openpic_realize(DeviceState *dev, Error **errp) {NULL} }; + if (opp->nb_cpus > MAX_CPU) { + error_set(errp, QERR_PROPERTY_VALUE_OUT_OF_RANGE, + TYPE_OPENPIC, "nb_cpus", (uint64_t)opp->nb_cpus, + (uint64_t)0, (uint64_t)MAX_CPU); + return; + } + switch (opp->model) { case OPENPIC_MODEL_FSL_MPIC_20: default: