From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41393) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZAXuI-0000lq-ML for qemu-devel@nongnu.org; Thu, 02 Jul 2015 02:23:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZAXuG-0002P9-HK for qemu-devel@nongnu.org; Thu, 02 Jul 2015 02:23:34 -0400 From: David Gibson Date: Thu, 2 Jul 2015 16:23:24 +1000 Message-Id: <1435818208-11808-24-git-send-email-david@gibson.dropbear.id.au> In-Reply-To: <1435818208-11808-1-git-send-email-david@gibson.dropbear.id.au> References: <1435818208-11808-1-git-send-email-david@gibson.dropbear.id.au> Subject: [Qemu-devel] [PATCH 23/27] spapr_vty: lookup should only return valid VTY objects List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: agraf@suse.de, afaerber@suse.de Cc: lvivier@redhat.com, thuth@redhat.com, aik@ozlabs.ru, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com, qemu-ppc@nongnu.org, bharata@linux.vnet.ibm.com, Greg Kurz , David Gibson If a guest passes the reg property of a valid VIO object that is not a VTY to either H_GET_TERM_CHAR or H_PUT_TERM_CHAR, QEMU hits a dynamic cast assertion and aborts. PAPR+ says "Hypervisor checks the termno parameter for validity against the Vterm IOA unit addresses assigned to the partition, else return H_Parameter." This patch adds a type check to ensure vty_lookup() either returns a pointer to a valid VTY object or NULL. H_GET_TERM_CHAR and H_PUT_TERM_CHAR will now return H_PARAMETER to the guest instead of crashing. The patch has no effect on the reg == 0 hack used to implement the RTAS call display-character. Signed-off-by: Greg Kurz Signed-off-by: David Gibson --- hw/char/spapr_vty.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/char/spapr_vty.c b/hw/char/spapr_vty.c index 1d53035..2d532af 100644 --- a/hw/char/spapr_vty.c +++ b/hw/char/spapr_vty.c @@ -228,6 +228,10 @@ VIOsPAPRDevice *vty_lookup(sPAPRMachineState *spapr, target_ulong reg) return spapr_vty_get_default(spapr->vio_bus); } + if (!object_dynamic_cast(OBJECT(sdev), TYPE_VIO_SPAPR_VTY_DEVICE)) { + return NULL; + } + return sdev; } -- 2.4.3