ghsa-pff2-hvq5-ccc8
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: ar9331: register the mdiobus under devres
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 ar9331 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 ar9331 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 ar9331 driver doesn't have a complex code structure for mdiobus removal, so just replace of_mdiobus_register with the devres variant in order to be all-devres and ensure that we don't free a still-registered bus.
{ "affected": [], "aliases": [ "CVE-2022-48817" ], "database_specific": { "cwe_ids": [], "github_reviewed": false, "github_reviewed_at": null, "nvd_published_at": "2024-07-16T12:15:05Z", "severity": null }, "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: ar9331: register the mdiobus under devres\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 ar9331 is an MDIO device, so the initial set of constraints that I\nthought would cause this (I2C or SPI buses which call -\u003eremove on\n-\u003eshutdown) do not apply. But there is one more which applies 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 ar9331 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 ar9331 driver doesn\u0027t have a complex code structure for mdiobus\nremoval, so just replace of_mdiobus_register with the devres variant in\norder to be all-devres and ensure that we don\u0027t free a still-registered\nbus.", "id": "GHSA-pff2-hvq5-ccc8", "modified": "2024-07-16T12:30:40Z", "published": "2024-07-16T12:30:40Z", "references": [ { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-48817" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/475ce5dcf2d88fd4f3c213a0ac944e3e40702970" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/50facd86e9fbc4b93fe02e5fe05776047f45dbfb" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/aae1c6a1d3d696fc33b609fb12fe744a556d1dc5" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/f1842a8cb71de4d7eb75a86f76e88c7ee739218c" } ], "schema_version": "1.4.0", "severity": [] }
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