| Message ID | 20200302040933.21789-1-pannengyuan@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio-serial-bus: do cleanup on the error path in realize() to avoid memleaks | expand |
Pan Nengyuan <pannengyuan@huawei.com> writes: > port->bh forgot to delete on the error path, this patch add it to fix memleaks. It's easy to reproduce as follow(add a same nr port): > {'execute': 'device_add', 'arguments': {'id': 'virtio_serial_pci0', 'driver': 'virtio-serial-pci', 'bus': 'pci.0', 'addr': '0x5'}, 'id': 'yVkZcGgV'} > {'execute': 'device_add', 'arguments': {'id': 'port1', 'driver': 'virtserialport', 'name': 'port1', 'chardev': 'channel1', 'bus': 'virtio_serial_pci0.0', 'nr': 1}, 'id': '3dXdUgJA'} > {'execute': 'device_add', 'arguments': {'id': 'port2', 'driver': 'virtserialport', 'name': 'port2', 'chardev': 'channel2', 'bus': 'virtio_serial_pci0.0', 'nr': 1}, 'id': 'qLzcCkob'} > {'execute': 'device_add', 'arguments': {'id': 'port2', 'driver': 'virtserialport', 'name': 'port2', 'chardev': 'channel2', 'bus': 'virtio_serial_pci0.0', 'nr': 2}, 'id': 'qLzcCkob'} > > The leak stack: > Direct leak of 40 byte(s) in 1 object(s) allocated from: > #0 0x7f04a8008ae8 in __interceptor_malloc (/lib64/libasan.so.5+0xefae8) > #1 0x7f04a73cf1d5 in g_malloc (/lib64/libglib-2.0.so.0+0x531d5) > #2 0x56273eaee484 in aio_bh_new /mnt/sdb/backup/qemu/util/async.c:125 > #3 0x56273eafe9a8 in qemu_bh_new /mnt/sdb/backup/qemu/util/main-loop.c:532 > #4 0x56273d52e62e in virtser_port_device_realize /mnt/sdb/backup/qemu/hw/char/virtio-serial-bus.c:946 > #5 0x56273dcc5040 in device_set_realized /mnt/sdb/backup/qemu/hw/core/qdev.c:891 > #6 0x56273e5ebbce in property_set_bool /mnt/sdb/backup/qemu/qom/object.c:2238 > #7 0x56273e5e5a9c in object_property_set /mnt/sdb/backup/qemu/qom/object.c:1324 > #8 0x56273e5ef5f8 in object_property_set_qobject /mnt/sdb/backup/qemu/qom/qom-qobject.c:26 > #9 0x56273e5e5e6a in object_property_set_bool /mnt/sdb/backup/qemu/qom/object.c:1390 > #10 0x56273daa40de in qdev_device_add /mnt/sdb/backup/qemu/qdev-monitor.c:680 > #11 0x56273daa53e9 in qmp_device_add /mnt/sdb/backup/qemu/qdev-monitor.c:805 > > Reported-by: Euler Robot <euler.robot@huawei.com> > Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com> Fixes: 199646d81522509ac2dba6d28c31e8c7d807bc93 > --- > hw/char/virtio-serial-bus.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c > index 941ed5aca9..563b845f71 100644 > --- a/hw/char/virtio-serial-bus.c > +++ b/hw/char/virtio-serial-bus.c > @@ -957,13 +957,13 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) > if (find_port_by_id(port->vser, port->id)) { > error_setg(errp, "virtio-serial-bus: A port already exists at id %u", > port->id); > - return; > + goto fail; > } > > if (port->name != NULL && find_port_by_name(port->name)) { > error_setg(errp, "virtio-serial-bus: A port already exists by name %s", > port->name); > - return; > + goto fail; > } > > if (port->id == VIRTIO_CONSOLE_BAD_ID) { > @@ -974,7 +974,7 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) > if (port->id == VIRTIO_CONSOLE_BAD_ID) { > error_setg(errp, "virtio-serial-bus: Maximum port limit for " > "this device reached"); > - return; > + goto fail; > } > } > } > @@ -983,16 +983,20 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) > if (port->id >= max_nr_ports) { > error_setg(errp, "virtio-serial-bus: Out-of-range port id specified, " > "max. allowed: %u", max_nr_ports - 1); > - return; > + goto fail; > } > > vsc->realize(dev, &err); > if (err != NULL) { > error_propagate(errp, err); > - return; > + goto fail; > } > > port->elem = NULL; > + return; > + > +fail: > + qemu_bh_delete(port->bh); > } > > static void virtser_port_device_plug(HotplugHandler *hotplug_dev, Looks correct to me. However, I wonder whether we could simply create port->bh later. It's for use by virtio_serial_throttle_port(), called on incoming migration via virtio_serial_load_device(), virtio_load(), virtio_device_get(). It runs flush_queued_data(), which does nothing unless virtio_queue_ready(port->ovq). Note that virtio_queue_ready() dereferences its argument. It's safe only after virtser_port_device_plug() set port->ovq. I'd expect that to be possible only while the device is realized. If that's correct, we could simply create port->bh last in virtser_port_device_realize().
On 3/4/2020 5:23 PM, Markus Armbruster wrote: > Pan Nengyuan <pannengyuan@huawei.com> writes: > >> port->bh forgot to delete on the error path, this patch add it to fix memleaks. It's easy to reproduce as follow(add a same nr port): >> {'execute': 'device_add', 'arguments': {'id': 'virtio_serial_pci0', 'driver': 'virtio-serial-pci', 'bus': 'pci.0', 'addr': '0x5'}, 'id': 'yVkZcGgV'} >> {'execute': 'device_add', 'arguments': {'id': 'port1', 'driver': 'virtserialport', 'name': 'port1', 'chardev': 'channel1', 'bus': 'virtio_serial_pci0.0', 'nr': 1}, 'id': '3dXdUgJA'} >> {'execute': 'device_add', 'arguments': {'id': 'port2', 'driver': 'virtserialport', 'name': 'port2', 'chardev': 'channel2', 'bus': 'virtio_serial_pci0.0', 'nr': 1}, 'id': 'qLzcCkob'} >> {'execute': 'device_add', 'arguments': {'id': 'port2', 'driver': 'virtserialport', 'name': 'port2', 'chardev': 'channel2', 'bus': 'virtio_serial_pci0.0', 'nr': 2}, 'id': 'qLzcCkob'} >> >> The leak stack: >> Direct leak of 40 byte(s) in 1 object(s) allocated from: >> #0 0x7f04a8008ae8 in __interceptor_malloc (/lib64/libasan.so.5+0xefae8) >> #1 0x7f04a73cf1d5 in g_malloc (/lib64/libglib-2.0.so.0+0x531d5) >> #2 0x56273eaee484 in aio_bh_new /mnt/sdb/backup/qemu/util/async.c:125 >> #3 0x56273eafe9a8 in qemu_bh_new /mnt/sdb/backup/qemu/util/main-loop.c:532 >> #4 0x56273d52e62e in virtser_port_device_realize /mnt/sdb/backup/qemu/hw/char/virtio-serial-bus.c:946 >> #5 0x56273dcc5040 in device_set_realized /mnt/sdb/backup/qemu/hw/core/qdev.c:891 >> #6 0x56273e5ebbce in property_set_bool /mnt/sdb/backup/qemu/qom/object.c:2238 >> #7 0x56273e5e5a9c in object_property_set /mnt/sdb/backup/qemu/qom/object.c:1324 >> #8 0x56273e5ef5f8 in object_property_set_qobject /mnt/sdb/backup/qemu/qom/qom-qobject.c:26 >> #9 0x56273e5e5e6a in object_property_set_bool /mnt/sdb/backup/qemu/qom/object.c:1390 >> #10 0x56273daa40de in qdev_device_add /mnt/sdb/backup/qemu/qdev-monitor.c:680 >> #11 0x56273daa53e9 in qmp_device_add /mnt/sdb/backup/qemu/qdev-monitor.c:805 >> >> Reported-by: Euler Robot <euler.robot@huawei.com> >> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com> > > Fixes: 199646d81522509ac2dba6d28c31e8c7d807bc93 > >> --- >> hw/char/virtio-serial-bus.c | 14 +++++++++----- >> 1 file changed, 9 insertions(+), 5 deletions(-) >> >> diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c >> index 941ed5aca9..563b845f71 100644 >> --- a/hw/char/virtio-serial-bus.c >> +++ b/hw/char/virtio-serial-bus.c >> @@ -957,13 +957,13 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) >> if (find_port_by_id(port->vser, port->id)) { >> error_setg(errp, "virtio-serial-bus: A port already exists at id %u", >> port->id); >> - return; >> + goto fail; >> } >> >> if (port->name != NULL && find_port_by_name(port->name)) { >> error_setg(errp, "virtio-serial-bus: A port already exists by name %s", >> port->name); >> - return; >> + goto fail; >> } >> >> if (port->id == VIRTIO_CONSOLE_BAD_ID) { >> @@ -974,7 +974,7 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) >> if (port->id == VIRTIO_CONSOLE_BAD_ID) { >> error_setg(errp, "virtio-serial-bus: Maximum port limit for " >> "this device reached"); >> - return; >> + goto fail; >> } >> } >> } >> @@ -983,16 +983,20 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) >> if (port->id >= max_nr_ports) { >> error_setg(errp, "virtio-serial-bus: Out-of-range port id specified, " >> "max. allowed: %u", max_nr_ports - 1); >> - return; >> + goto fail; >> } >> >> vsc->realize(dev, &err); >> if (err != NULL) { >> error_propagate(errp, err); >> - return; >> + goto fail; >> } >> >> port->elem = NULL; >> + return; >> + >> +fail: >> + qemu_bh_delete(port->bh); >> } >> >> static void virtser_port_device_plug(HotplugHandler *hotplug_dev, > > Looks correct to me. > > However, I wonder whether we could simply create port->bh later. It's > for use by virtio_serial_throttle_port(), called on incoming migration > via virtio_serial_load_device(), virtio_load(), virtio_device_get(). It > runs flush_queued_data(), which does nothing unless > virtio_queue_ready(port->ovq). > > Note that virtio_queue_ready() dereferences its argument. It's safe > only after virtser_port_device_plug() set port->ovq. I'd expect that to > be possible only while the device is realized. If that's correct, we > could simply create port->bh last in virtser_port_device_realize(). Yes, it looks correct. If there is no other points, I will change it. Thanks. > > . >
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c index 941ed5aca9..563b845f71 100644 --- a/hw/char/virtio-serial-bus.c +++ b/hw/char/virtio-serial-bus.c @@ -957,13 +957,13 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) if (find_port_by_id(port->vser, port->id)) { error_setg(errp, "virtio-serial-bus: A port already exists at id %u", port->id); - return; + goto fail; } if (port->name != NULL && find_port_by_name(port->name)) { error_setg(errp, "virtio-serial-bus: A port already exists by name %s", port->name); - return; + goto fail; } if (port->id == VIRTIO_CONSOLE_BAD_ID) { @@ -974,7 +974,7 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) if (port->id == VIRTIO_CONSOLE_BAD_ID) { error_setg(errp, "virtio-serial-bus: Maximum port limit for " "this device reached"); - return; + goto fail; } } } @@ -983,16 +983,20 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) if (port->id >= max_nr_ports) { error_setg(errp, "virtio-serial-bus: Out-of-range port id specified, " "max. allowed: %u", max_nr_ports - 1); - return; + goto fail; } vsc->realize(dev, &err); if (err != NULL) { error_propagate(errp, err); - return; + goto fail; } port->elem = NULL; + return; + +fail: + qemu_bh_delete(port->bh); } static void virtser_port_device_plug(HotplugHandler *hotplug_dev,
port->bh forgot to delete on the error path, this patch add it to fix memleaks. It's easy to reproduce as follow(add a same nr port): {'execute': 'device_add', 'arguments': {'id': 'virtio_serial_pci0', 'driver': 'virtio-serial-pci', 'bus': 'pci.0', 'addr': '0x5'}, 'id': 'yVkZcGgV'} {'execute': 'device_add', 'arguments': {'id': 'port1', 'driver': 'virtserialport', 'name': 'port1', 'chardev': 'channel1', 'bus': 'virtio_serial_pci0.0', 'nr': 1}, 'id': '3dXdUgJA'} {'execute': 'device_add', 'arguments': {'id': 'port2', 'driver': 'virtserialport', 'name': 'port2', 'chardev': 'channel2', 'bus': 'virtio_serial_pci0.0', 'nr': 1}, 'id': 'qLzcCkob'} {'execute': 'device_add', 'arguments': {'id': 'port2', 'driver': 'virtserialport', 'name': 'port2', 'chardev': 'channel2', 'bus': 'virtio_serial_pci0.0', 'nr': 2}, 'id': 'qLzcCkob'} The leak stack: Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f04a8008ae8 in __interceptor_malloc (/lib64/libasan.so.5+0xefae8) #1 0x7f04a73cf1d5 in g_malloc (/lib64/libglib-2.0.so.0+0x531d5) #2 0x56273eaee484 in aio_bh_new /mnt/sdb/backup/qemu/util/async.c:125 #3 0x56273eafe9a8 in qemu_bh_new /mnt/sdb/backup/qemu/util/main-loop.c:532 #4 0x56273d52e62e in virtser_port_device_realize /mnt/sdb/backup/qemu/hw/char/virtio-serial-bus.c:946 #5 0x56273dcc5040 in device_set_realized /mnt/sdb/backup/qemu/hw/core/qdev.c:891 #6 0x56273e5ebbce in property_set_bool /mnt/sdb/backup/qemu/qom/object.c:2238 #7 0x56273e5e5a9c in object_property_set /mnt/sdb/backup/qemu/qom/object.c:1324 #8 0x56273e5ef5f8 in object_property_set_qobject /mnt/sdb/backup/qemu/qom/qom-qobject.c:26 #9 0x56273e5e5e6a in object_property_set_bool /mnt/sdb/backup/qemu/qom/object.c:1390 #10 0x56273daa40de in qdev_device_add /mnt/sdb/backup/qemu/qdev-monitor.c:680 #11 0x56273daa53e9 in qmp_device_add /mnt/sdb/backup/qemu/qdev-monitor.c:805 Reported-by: Euler Robot <euler.robot@huawei.com> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com> --- hw/char/virtio-serial-bus.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)