CVE-2022-48818
net: dsa: mv88e6xxx: don't use devres for mdiobus
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: net: dsa: mv88e6xxx: don't use devres for mdiobus As explained in commits: 74b6d7d13307 ("net: dsa: realtek: register the MDIO bus under devres") 5135e96a3dd2 ("net: dsa: don't allocate the slave_mii_bus using devres") mdiobus_free() will panic when called from devm_mdiobus_free() <- devres_release_all() <- __device_release_driver(), and that mdiobus was not previously unregistered. The mv88e6xxx is an MDIO device, so the initial set of constraints that I thought would cause this (I2C or SPI buses which call ->remove on ->shutdown) do not apply. But there is one more which applies here. If the DSA master itself is on a bus that calls ->remove from ->shutdown (like dpaa2-eth, which is on the fsl-mc bus), there is a device link between the switch and the DSA master, and device_links_unbind_consumers() will unbind the Marvell switch driver on shutdown. systemd-shutdown[1]: Powering off. mv88e6085 0x0000000008b96000:00 sw_gl0: Link is Down fsl-mc dpbp.9: Removing from iommu group 7 fsl-mc dpbp.8: Removing from iommu group 7 ------------[ cut here ]------------ kernel BUG at drivers/net/phy/mdio_bus.c:677! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.16.5-00040-gdc05f73788e5 #15 pc : mdiobus_free+0x44/0x50 lr : devm_mdiobus_free+0x10/0x20 Call trace: mdiobus_free+0x44/0x50 devm_mdiobus_free+0x10/0x20 devres_release_all+0xa0/0x100 __device_release_driver+0x190/0x220 device_release_driver_internal+0xac/0xb0 device_links_unbind_consumers+0xd4/0x100 __device_release_driver+0x4c/0x220 device_release_driver_internal+0xac/0xb0 device_links_unbind_consumers+0xd4/0x100 __device_release_driver+0x94/0x220 device_release_driver+0x28/0x40 bus_remove_device+0x118/0x124 device_del+0x174/0x420 fsl_mc_device_remove+0x24/0x40 __fsl_mc_device_remove+0xc/0x20 device_for_each_child+0x58/0xa0 dprc_remove+0x90/0xb0 fsl_mc_driver_remove+0x20/0x5c __device_release_driver+0x21c/0x220 device_release_driver+0x28/0x40 bus_remove_device+0x118/0x124 device_del+0x174/0x420 fsl_mc_bus_remove+0x80/0x100 fsl_mc_bus_shutdown+0xc/0x1c platform_shutdown+0x20/0x30 device_shutdown+0x154/0x330 kernel_power_off+0x34/0x6c __do_sys_reboot+0x15c/0x250 __arm64_sys_reboot+0x20/0x30 invoke_syscall.constprop.0+0x4c/0xe0 do_el0_svc+0x4c/0x150 el0_svc+0x24/0xb0 el0t_64_sync_handler+0xa8/0xb0 el0t_64_sync+0x178/0x17c So the same treatment must be applied to all DSA switch drivers, which is: either use devres for both the mdiobus allocation and registration, or don't use devres at all. The Marvell driver already has a good structure for mdiobus removal, so just plug in mdiobus_free and get rid of devres.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.27% · top 80% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected ac3a68d56651c3dad2c12c7afce065fe15267f44 – < 8ccebe77df6e0d88c72ba5e69cf1835927e53b6c
- affected ac3a68d56651c3dad2c12c7afce065fe15267f44 – < 8b626d45127d6f5ada7d815b83cfdc09e8cb1394
- affected ac3a68d56651c3dad2c12c7afce065fe15267f44 – < 1b451c3994a2d322f8e55032c62c8b47b7d95900
- affected ac3a68d56651c3dad2c12c7afce065fe15267f44 – < f53a2ce893b2c7884ef94471f170839170a4eba0
- affected 5.9
- unaffected < 5.9
- unaffected 5.10.101 – ≤ 5.10.*
- unaffected 5.15.24 – ≤ 5.15.*
- unaffected 5.16.10 – ≤ 5.16.*
- unaffected 5.17 – ≤ *
References (4)
- https://git.kernel.org/stable/c/8ccebe77df6e0d88c72ba5e69cf1835927e53b6c (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/8b626d45127d6f5ada7d815b83cfdc09e8cb1394 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/1b451c3994a2d322f8e55032c62c8b47b7d95900 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/f53a2ce893b2c7884ef94471f170839170a4eba0 (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2022-48818)Record last updated .