From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57663) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X9bxu-0001iq-JD for qemu-devel@nongnu.org; Tue, 22 Jul 2014 11:27:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X9bxn-0003ly-4P for qemu-devel@nongnu.org; Tue, 22 Jul 2014 11:26:54 -0400 From: Laszlo Ersek Date: Tue, 22 Jul 2014 17:26:41 +0200 Message-Id: <1406042801-28212-1-git-send-email-lersek@redhat.com> Subject: [Qemu-devel] [PATCH for-2.1 for-stable] vmstate_xhci_event: fix unterminated field list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: lersek@redhat.com, amit.shah@redhat.com, dgilbert@redhat.com, kraxel@redhat.com, qemu-devel@nongnu.org, qemu-stable@nongnu.org "vmstate_xhci_event" was introduced in commit 37352df3 ("xhci: add live migration support"), and first released in v1.6.0. The field list in this VMSD is not terminated with the VMSTATE_END_OF_LIST() macro. During normal use (ie. migration), the issue is practically invisible, because the "vmstate_xhci_event" object (with the unterminated field list) is only ever referenced -- via "vmstate_xhci_intr" -- if xhci_er_full() returns true, for the "ev_buffer" test. Since that field_exists() check (apparently) almost always returns false, we almost never traverse "vmstate_xhci_event" during migration, which hides the bug. However, Amit's vmstate checker forces recursion into this VMSD as well, and the lack of VMSTATE_END_OF_LIST() breaks the field list terminator check (field->name != NULL) in dump_vmstate_vmsd(). The result is undefined behavior, which in my case translates to infinite recursion (because the loop happens to overflow into "vmstate_xhci_intr", which then links back to "vmstate_xhci_event"). Add the missing terminator. Signed-off-by: Laszlo Ersek --- hw/usb/hcd-xhci.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c index 7f2af89..58c4b11 100644 --- a/hw/usb/hcd-xhci.c +++ b/hw/usb/hcd-xhci.c @@ -3737,6 +3737,7 @@ static const VMStateDescription vmstate_xhci_event = { VMSTATE_UINT32(flags, XHCIEvent), VMSTATE_UINT8(slotid, XHCIEvent), VMSTATE_UINT8(epid, XHCIEvent), + VMSTATE_END_OF_LIST() } }; -- 1.8.3.1