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* [Qemu-devel] [PATCH v2] virtio-balloon: fix integer overflow in memory stats feature
@ 2014-09-16 13:39 Luiz Capitulino
  2014-09-16 13:55 ` Eric Blake
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Luiz Capitulino @ 2014-09-16 13:39 UTC (permalink / raw)
  To: qemu-devel; +Cc: qemu-stable, armbru

When a QMP client changes the polling interval time by setting
the guest-stats-polling-interval property, the interval value
is stored and manipulated as an int64_t variable.

However, the balloon_stats_change_timer() function, which is
used to set the actual timer with the interval value, takes
an int instead, causing an overflow for big interval values.

This commit fix this bug by changing balloon_stats_change_timer()
to take an int64_t and also it limits the polling interval value
to UINT_MAX to avoid other kinds of overflow.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 hw/virtio/virtio-balloon.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 2c30b3d..b5cf7ca 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -87,7 +87,7 @@ static void balloon_stats_destroy_timer(VirtIOBalloon *s)
     }
 }
 
-static void balloon_stats_change_timer(VirtIOBalloon *s, int secs)
+static void balloon_stats_change_timer(VirtIOBalloon *s, int64_t secs)
 {
     timer_mod(s->stats_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + secs * 1000);
 }
@@ -170,6 +170,11 @@ static void balloon_stats_set_poll_interval(Object *obj, struct Visitor *v,
         return;
     }
 
+    if (value > UINT_MAX) {
+        error_setg(errp, "timer value is too big");
+        return;
+    }
+
     if (value == s->stats_poll_interval) {
         return;
     }
-- 
1.9.3

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2014-09-16 15:08 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-09-16 13:39 [Qemu-devel] [PATCH v2] virtio-balloon: fix integer overflow in memory stats feature Luiz Capitulino
2014-09-16 13:55 ` Eric Blake
2014-09-16 15:02 ` Michael S. Tsirkin
2014-09-16 14:02   ` Luiz Capitulino
2014-09-16 15:08 ` Markus Armbruster

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