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[Qemu-devel] [PULL 03/11] usb: ohci: limit the number of link eds
From: |
Gerd Hoffmann |
Subject: |
[Qemu-devel] [PULL 03/11] usb: ohci: limit the number of link eds |
Date: |
Tue, 21 Feb 2017 08:16:17 +0100 |
From: Li Qiang <address@hidden>
The guest may builds an infinite loop with link eds. This patch
limit the number of linked ed to avoid this.
Signed-off-by: Li Qiang <address@hidden>
Message-id: address@hidden
Signed-off-by: Gerd Hoffmann <address@hidden>
---
hw/usb/hcd-ohci.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
index 2cba3e3..21c93e0 100644
--- a/hw/usb/hcd-ohci.c
+++ b/hw/usb/hcd-ohci.c
@@ -42,6 +42,8 @@
#define OHCI_MAX_PORTS 15
+#define ED_LINK_LIMIT 4
+
static int64_t usb_frame_time;
static int64_t usb_bit_time;
@@ -1184,7 +1186,7 @@ static int ohci_service_ed_list(OHCIState *ohci, uint32_t
head, int completion)
uint32_t next_ed;
uint32_t cur;
int active;
-
+ uint32_t link_cnt = 0;
active = 0;
if (head == 0)
@@ -1199,6 +1201,11 @@ static int ohci_service_ed_list(OHCIState *ohci,
uint32_t head, int completion)
next_ed = ed.next & OHCI_DPTR_MASK;
+ if (++link_cnt > ED_LINK_LIMIT) {
+ ohci_die(ohci);
+ return 0;
+ }
+
if ((ed.head & OHCI_ED_H) || (ed.flags & OHCI_ED_K)) {
uint32_t addr;
/* Cancel pending packets for ED that have been paused. */
--
1.8.3.1
- [Qemu-devel] [PULL 00/11] usb patch queue, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 07/11] xhci: fix nec vendor quirk handling, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 03/11] usb: ohci: limit the number of link eds,
Gerd Hoffmann <=
- [Qemu-devel] [PULL 06/11] xhci: add qemu xhci controller, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 05/11] xhci: drop ER_FULL_HACK workaround, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 01/11] usb: ehci: fix memory leak in ehci, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 04/11] xhci: apply limits to loops, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 10/11] usb-ccid: move header size check, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 09/11] usb-ccid: better bulk_out error handling, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 08/11] xhci: drop via vendor command handling, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 02/11] usb: ohci: fix error return code in servicing iso td, Gerd Hoffmann, 2017/02/21
- [Qemu-devel] [PULL 11/11] usb-ccid: add check message size checks, Gerd Hoffmann, 2017/02/21
- Re: [Qemu-devel] [PULL 00/11] usb patch queue, Peter Maydell, 2017/02/21