CVE-2022-50545 r6040: Fix kmemleak in probe and remove
A memory leak in the r6040 network driver can lead to resource exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50545?
CVE-2022-50545 is a medium-severity memory corruption vulnerability in Linux kernel, published on 7 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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: [<ffffffff815bcd82>] kmalloc_trace+0x22/0x60 [<ffffffff827e20ee>] phy_device_create+0x4e/0x90 [<ffffffff827e6072>] get_phy_device+0xd2/0x220 [<ffffffff827e7844>] mdiobus_scan+0xa4/0x2e0 [<ffffffff827e8be2>] __mdiobus_register+0x482/0x8b0 [<ffffffffa01f5d24>] 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 <- fault inject succeeded, goto error handling path
// error handling path err_out_mdio_unregister: mdiobus_unregister(lp->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.
Weakness: CWE-401
Which versions are affected by CVE-2022-50545?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50545?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2022-50545 being exploited?
There is no known exploitation of CVE-2022-50545 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50545, GHSA-2q87-gcq9-5rfq, UBUNTU-CVE-2022-50545.