From 5a0948d36c4cbc1c5534afac6fee99de55245d12 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Sat, 30 Nov 2019 20:42:21 +0100 Subject: [PATCH] net/virtio: Fix failover error handling crash bugs Functions that take an Error ** parameter to pass an error to the caller expect the parameter to point to null. failover_replug_primary() violates this precondition in several places: * After qemu_opts_from_qdict() failed, *errp is no longer null. Passing it to error_setg() is wrong, and will trip the assertion in error_setv(). Messed up in commit 150ab54aa6 "net/virtio: fix re-plugging of primary device". Simply drop the error_setg(). * Passing @errp to qemu_opt_set_bool(), hotplug_handler_pre_plug(), and hotplug_handler_plug() is wrong. If one of the first two fails, *errp is no longer null. Risks tripping the same assertion. Moreover, continuing after such errors is unsafe. Messed up in commit 9711cd0dfc "net/virtio: add failover support". Fix by handling each error properly. failover_replug_primary() crashes when passed a null @errp. Also messed up in commit 9711cd0dfc. This bug can't bite as no caller actually passes null. Fix it anyway. Fixes: 9711cd0dfc3fa414f7f64935713c07134ae67971 Fixes: 150ab54aa6934583180f88a2bd540bc6fc4fbff3 Cc: Jens Freimann Cc: Michael S. Tsirkin Signed-off-by: Markus Armbruster Message-Id: <20191130194240.10517-3-armbru@redhat.com> Reviewed-by: Jens Freimann --- hw/net/virtio-net.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 87088ba374..db3d7c38e6 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -2795,6 +2795,7 @@ static bool failover_unplug_primary(VirtIONet *n) static bool failover_replug_primary(VirtIONet *n, Error **errp) { + Error *err = NULL; HotplugHandler *hotplug_ctrl; PCIDevice *pdev = PCI_DEVICE(n->primary_dev); @@ -2806,27 +2807,33 @@ static bool failover_replug_primary(VirtIONet *n, Error **errp) qemu_find_opts("device"), n->primary_device_dict, errp); if (!n->primary_device_opts) { - error_setg(errp, "virtio_net: couldn't find primary device opts"); - goto out; + return false; } } n->primary_bus = n->primary_dev->parent_bus; if (!n->primary_bus) { error_setg(errp, "virtio_net: couldn't find primary bus"); - goto out; + return false; } qdev_set_parent_bus(n->primary_dev, n->primary_bus); n->primary_should_be_hidden = false; qemu_opt_set_bool(n->primary_device_opts, - "partially_hotplugged", true, errp); + "partially_hotplugged", true, &err); + if (err) { + goto out; + } hotplug_ctrl = qdev_get_hotplug_handler(n->primary_dev); if (hotplug_ctrl) { - hotplug_handler_pre_plug(hotplug_ctrl, n->primary_dev, errp); + hotplug_handler_pre_plug(hotplug_ctrl, n->primary_dev, &err); + if (err) { + goto out; + } hotplug_handler_plug(hotplug_ctrl, n->primary_dev, errp); } out: - return *errp == NULL; + error_propagate(errp, err); + return !err; } static void virtio_net_handle_migration_primary(VirtIONet *n,