From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41609) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cZGzb-00013t-Bs for qemu-devel@nongnu.org; Thu, 02 Feb 2017 08:00:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cZGza-00005k-By for qemu-devel@nongnu.org; Thu, 02 Feb 2017 08:00:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51774) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cZGza-0008W0-4G for qemu-devel@nongnu.org; Thu, 02 Feb 2017 08:00:02 -0500 Received: from smtp.corp.redhat.com (int-mx16.intmail.prod.int.phx2.redhat.com [10.5.11.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3C79481222 for ; Thu, 2 Feb 2017 13:00:02 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" Date: Thu, 2 Feb 2017 12:59:55 +0000 Message-Id: <20170202125956.21942-3-dgilbert@redhat.com> In-Reply-To: <20170202125956.21942-1-dgilbert@redhat.com> References: <20170202125956.21942-1-dgilbert@redhat.com> Subject: [Qemu-devel] [PATCH v2 2/3] migration: Check for ID length List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, quintela@redhat.com, amit.shah@redhat.com From: "Dr. David Alan Gilbert" The qdev id of a device can be huge if it's on the end of a chain of bridges; in reality such chains shouldn't occur but they can be made to by chaining PCIe bridges together. The migration format has a number of 256 character long format limits; check we don't hit them (we already use pstrcat/cpy but that just protects us from buffer overruns, we fairly quickly hit an assert). Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela --- include/migration/vmstate.h | 2 ++ migration/savevm.c | 21 ++++++++++++++++----- 2 files changed, 18 insertions(+), 5 deletions(-) diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index c38b00a..6233fe2 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -985,12 +985,14 @@ void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, bool vmstate_save_needed(const VMStateDescription *vmsd, void *opaque); +/* Returns: 0 on success, -1 on failure */ int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, const VMStateDescription *vmsd, void *base, int alias_id, int required_for_version, Error **errp); +/* Returns: 0 on success, -1 on failure */ static inline int vmstate_register(DeviceState *dev, int instance_id, const VMStateDescription *vmsd, void *opaque) diff --git a/migration/savevm.c b/migration/savevm.c index 59928d6..e8e5ff5 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -590,8 +590,14 @@ int register_savevm_live(DeviceState *dev, if (dev) { char *id = qdev_get_dev_path(dev); if (id) { - pstrcpy(se->idstr, sizeof(se->idstr), id); - pstrcat(se->idstr, sizeof(se->idstr), "/"); + if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= + sizeof(se->idstr)) { + error_report("Path too long for VMState (%s)", id); + g_free(id); + g_free(se); + + return -1; + } g_free(id); se->compat = g_new0(CompatEntry, 1); @@ -674,9 +680,14 @@ int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, if (dev) { char *id = qdev_get_dev_path(dev); if (id) { - pstrcpy(se->idstr, sizeof(se->idstr), id); - pstrcat(se->idstr, sizeof(se->idstr), "/"); - g_free(id); + if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >= + sizeof(se->idstr)) { + error_setg(errp, "Path too long for VMState (%s)", id); + g_free(id); + g_free(se); + + return -1; + } se->compat = g_new0(CompatEntry, 1); pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name); -- 2.9.3