From 63ce53724637e2e7ba51fe3a4f78351715049905 Mon Sep 17 00:00:00 2001 From: Ma Ke Date: Sat, 19 Jul 2025 15:58:56 +0800 Subject: [PATCH] sunvdc: Balance device refcount in vdc_port_mpgroup_check MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Using device_find_child() to locate a probed virtual-device-port node causes a device refcount imbalance, as device_find_child() internally calls get_device() to increment the device’s reference count before returning its pointer. vdc_port_mpgroup_check() directly returns true upon finding a matching device without releasing the reference via put_device(). We should call put_device() to decrement refcount. As comment of device_find_child() says, 'NOTE: you will need to drop the reference with put_device() after use'. Found by code review. Cc: stable@vger.kernel.org Fixes: 3ee70591d6c4 ("sunvdc: prevent sunvdc panic when mpgroup disk added to guest domain") Signed-off-by: Ma Ke Link: https://lore.kernel.org/r/20250719075856.3447953-1-make24@iscas.ac.cn Signed-off-by: Jens Axboe --- drivers/block/sunvdc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c index b5727dea15bde..7af21fe676717 100644 --- a/drivers/block/sunvdc.c +++ b/drivers/block/sunvdc.c @@ -957,8 +957,10 @@ static bool vdc_port_mpgroup_check(struct vio_dev *vdev) dev = device_find_child(vdev->dev.parent, &port_data, vdc_device_probed); - if (dev) + if (dev) { + put_device(dev); return true; + } return false; } -- 2.47.2