Description

In the Linux kernel, the following vulnerability has been resolved: r6040: Fix kmemleak in probe and remove There is a memory leaks reported by kmemleak: unreferenced object 0xffff888116111000 (size 2048): comm "modprobe", pid 817, jiffies 4294759745 (age 76.502s) hex dump (first 32 bytes): 00 c4 0a 04 81 88 ff ff 08 10 11 16 81 88 ff ff ................ 08 10 11 16 81 88 ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [] kmalloc_trace+0x22/0x60 [] phy_device_create+0x4e/0x90 [] get_phy_device+0xd2/0x220 [] mdiobus_scan+0xa4/0x2e0 [] __mdiobus_register+0x482/0x8b0 [] r6040_init_one+0x714/0xd2c [r6040] ... The problem occurs in probe process as follows: r6040_init_one: mdiobus_register mdiobus_scan <- alloc and register phy_device, the reference count of phy_device is 3 r6040_mii_probe phy_connect <- connect to the first phy_device, so the reference count of the first phy_device is 4, others are 3 register_netdev mii_bus); err_out_mdio: mdiobus_free(lp->mii_bus); <- the reference count of the first phy_device is 1, it is not released and other phy_devices are released // similarly, the remove process also has the same problem The root cause is traced to the phy_device is not disconnected when removes one r6040 device in r6040_remove_one() or on error handling path after r6040_mii probed successfully. In r6040_mii_probe(), a net ethernet device is connected to the first PHY device of mii_bus, in order to notify the connected driver when the link status changes, which is the default behavior of the PHY infrastructure to handle everything. Therefore the phy_device should be disconnected when removes one r6040 device or on error handling path. Fix it by adding phy_disconnect() when removes one r6040 device or on error handling path after r6040_mii probed successfully.

Severity MEDIUM

CVSS Score 5.5

CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE CWE-401

Public Exploit ✅ No

Source NVD

Published 2025-10-07

Updated 2026-06-08

Modified 2026-02-26

Fix URL https://git.kernel.org/stable/c/2ce242e1b9ad31c1f68496b3548e407a8cb2c07d

Software	From version	Fixed in
linux-kernel	6.1	6.1.2