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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2022-50545

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…

MEDIUM 5.5EPSS 0.21%

Does this matter?

Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.21% probability · 11th percentile
CISA KEV
Not listed
Weakness
CWE-401
Affected
linux/linux kernel
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.