From 4b41911968cb53458b86b027f0d028e38618df46 Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Wed, 14 May 2014 08:52:54 +0200 Subject: [PATCH 23/31] hpet: fix buffer overrun on invalid state load RH-Author: Michael S. Tsirkin Message-id: <1400057538-6975-5-git-send-email-mst@redhat.com> Patchwork-id: 58871 O-Subject: [PATCH qemu-kvm RHEL7.1 4/5] hpet: fix buffer overrun on invalid state load Bugzilla: 1095707 RH-Acked-by: Dr. David Alan Gilbert (git) RH-Acked-by: Marcel Apfelbaum RH-Acked-by: Paolo Bonzini RH-Acked-by: Juan Quintela CVE-2013-4527 hw/timer/hpet.c buffer overrun hpet is a VARRAY with a uint8 size but static array of 32 To fix, make sure num_timers is valid using VMSTATE_VALID hook. Reported-by: Anthony Liguori Signed-off-by: Michael S. Tsirkin Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Juan Quintela (cherry picked from commit 3f1c49e2136fa08ab1ef3183fd55def308829584) Tested: lightly on developer's box Brew build: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=7452039 Bugzilla:1095707 --- hw/timer/hpet.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) Signed-off-by: Miroslav Rezanina --- hw/timer/hpet.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-) diff --git a/hw/timer/hpet.c b/hw/timer/hpet.c index dd486a1..54ffa49 100644 --- a/hw/timer/hpet.c +++ b/hw/timer/hpet.c @@ -222,6 +222,18 @@ static int hpet_pre_load(void *opaque) return 0; } +static bool hpet_validate_num_timers(void *opaque, int version_id) +{ + HPETState *s = opaque; + + if (s->num_timers < HPET_MIN_TIMERS) { + return false; + } else if (s->num_timers > HPET_MAX_TIMERS) { + return false; + } + return true; +} + static int hpet_post_load(void *opaque, int version_id) { HPETState *s = opaque; @@ -290,6 +302,7 @@ static const VMStateDescription vmstate_hpet = { VMSTATE_UINT64(isr, HPETState), VMSTATE_UINT64(hpet_counter, HPETState), VMSTATE_UINT8_V(num_timers, HPETState, 2), + VMSTATE_VALIDATE("num_timers in range", hpet_validate_num_timers), VMSTATE_STRUCT_VARRAY_UINT8(timer, HPETState, num_timers, 0, vmstate_hpet_timer, HPETTimer), VMSTATE_END_OF_LIST() -- 1.7.1