phydev->drv can become NULL while the phy_device is still attached to its net_device, namely after the PHY driver is unbound via sysfs: echo > /sys/bus/mdio_bus/drivers//unbind phy_remove() clears phydev->drv but doesn't call phy_detach(), so the phy_device stays in the link topology xarray and ethnl_req_get_phydev() still hands it back. ETHTOOL_MSG_PHY_GET then oopses on: rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL); drvname is already treated as optional by phy_reply_size(), phy_fill_reply() and phy_cleanup_data(), so just skip the allocation when there is no driver bound. Fixes: 9dd2ad5e92b9 ("net: ethtool: phy: Convert the PHY_GET command to generic phy dump") Cc: stable@vger.kernel.org # 6.13.x Signed-off-by: David Carlier --- net/ethtool/phy.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c index f76d94d848d6..ddc6eab701ed 100644 --- a/net/ethtool/phy.c +++ b/net/ethtool/phy.c @@ -94,10 +94,12 @@ static int phy_prepare_data(const struct ethnl_req_info *req_info, if (!rep_data->name) return -ENOMEM; - rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL); - if (!rep_data->drvname) { - ret = -ENOMEM; - goto err_free_name; + if (phydev->drv) { + rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL); + if (!rep_data->drvname) { + ret = -ENOMEM; + goto err_free_name; + } } rep_data->upstream_type = pdn->upstream_type; -- 2.53.0