GHSA-4WGH-6F55-V67R
Vulnerability from github – Published: 2024-07-16 12:30 – Updated: 2025-10-03 15:31In the Linux kernel, the following vulnerability has been resolved:
net: dsa: felix: 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 Felix VSC9959 switch is a PCI 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 felix switch driver on shutdown.
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 felix driver has the code structure in place for orderly mdiobus removal, so just replace devm_mdiobus_alloc_size() with the non-devres variant, and add manual free where necessary, to ensure that we don't let devres free a still-registered bus.
{
"affected": [],
"aliases": [
"CVE-2022-48813"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-16T12:15:05Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: felix: don\u0027t use devres for mdiobus\n\nAs explained in commits:\n74b6d7d13307 (\"net: dsa: realtek: register the MDIO bus under devres\")\n5135e96a3dd2 (\"net: dsa: don\u0027t allocate the slave_mii_bus using devres\")\n\nmdiobus_free() will panic when called from devm_mdiobus_free() \u003c-\ndevres_release_all() \u003c- __device_release_driver(), and that mdiobus was\nnot previously unregistered.\n\nThe Felix VSC9959 switch is a PCI device, so the initial set of\nconstraints that I thought would cause this (I2C or SPI buses which call\n-\u003eremove on -\u003eshutdown) do not apply. But there is one more which\napplies here.\n\nIf the DSA master itself is on a bus that calls -\u003eremove from -\u003eshutdown\n(like dpaa2-eth, which is on the fsl-mc bus), there is a device link\nbetween the switch and the DSA master, and device_links_unbind_consumers()\nwill unbind the felix switch driver on shutdown.\n\nSo the same treatment must be applied to all DSA switch drivers, which\nis: either use devres for both the mdiobus allocation and registration,\nor don\u0027t use devres at all.\n\nThe felix driver has the code structure in place for orderly mdiobus\nremoval, so just replace devm_mdiobus_alloc_size() with the non-devres\nvariant, and add manual free where necessary, to ensure that we don\u0027t\nlet devres free a still-registered bus.",
"id": "GHSA-4wgh-6f55-v67r",
"modified": "2025-10-03T15:31:14Z",
"published": "2024-07-16T12:30:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-48813"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/209bdb7ec6a28c7cdf580a0a98afbc9fc3b98932"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8cda7577a0b4018572f31e0caadfabd305ea2786"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/95e5402f9430b3c7d885dd3ec4c8c02c17936923"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9db6f056efd089e80d81c774c01b639adf30c097"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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