From: Mauro Matteo Cascella <mcascell@redhat.com>
To: qemu-devel@nongnu.org
Cc: gaoning.pgn@antgroup.com, mcascell@redhat.com,
linyi.lxw@antfin.com, kraxel@redhat.com, pauldzim@gmail.com
Subject: [PATCH] hw/usb/hcd-dwc2: fix divide-by-zero in dwc2_handle_packet()
Date: Mon, 12 Oct 2020 17:03:56 +0200 [thread overview]
Message-ID: <20201012150356.79670-1-mcascell@redhat.com> (raw)
Check the value of mps before it is used as divisor. Since HCCHAR_MPS is guest
controllable, this prevents a malicious/buggy guest from crashing the QEMU
process on the host.
Signed-off-by: Mauro Matteo Cascella <mcascell@redhat.com>
Reported-by: Gaoning Pan <gaoning.pgn@antgroup.com>
Reported-by: Xingwei Lin <linyi.lxw@antfin.com>
---
hw/usb/hcd-dwc2.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/hw/usb/hcd-dwc2.c b/hw/usb/hcd-dwc2.c
index 97688d21bf..91476fd781 100644
--- a/hw/usb/hcd-dwc2.c
+++ b/hw/usb/hcd-dwc2.c
@@ -324,6 +324,12 @@ babble:
}
}
+ if (mps == 0) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: Bad HCCHAR_MPS set to zero\n", __func__);
+ return;
+ }
+
tpcnt = actual / mps;
if (actual % mps) {
tpcnt++;
--
2.26.2
next reply other threads:[~2020-10-12 15:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 15:03 Mauro Matteo Cascella [this message]
2020-10-12 20:34 ` [PATCH] hw/usb/hcd-dwc2: fix divide-by-zero in dwc2_handle_packet() Paul Zimmerman
2020-10-13 7:04 ` Gerd Hoffmann
2020-10-13 7:19 ` Paul Zimmerman
2020-10-13 8:41 ` Gerd Hoffmann
2020-10-14 19:55 ` Mauro Matteo Cascella
2020-10-15 7:35 ` Paul Zimmerman
2020-10-15 10:17 ` Gerd Hoffmann
2020-10-14 12:06 ` Gerd Hoffmann
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