ghsa-j4rr-5cq7-mpjq
Vulnerability from github
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.
{
"affected": [],
"aliases": [
"CVE-2022-48818"
],
"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: mv88e6xxx: 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 mv88e6xxx is an MDIO device, so the initial set of constraints that\nI thought 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 Marvell switch driver on shutdown.\n\nsystemd-shutdown[1]: Powering off.\nmv88e6085 0x0000000008b96000:00 sw_gl0: Link is Down\nfsl-mc dpbp.9: Removing from iommu group 7\nfsl-mc dpbp.8: Removing from iommu group 7\n------------[ cut here ]------------\nkernel BUG at drivers/net/phy/mdio_bus.c:677!\nInternal error: Oops - BUG: 0 [#1] PREEMPT SMP\nModules linked in:\nCPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 5.16.5-00040-gdc05f73788e5 #15\npc : mdiobus_free+0x44/0x50\nlr : devm_mdiobus_free+0x10/0x20\nCall trace:\n mdiobus_free+0x44/0x50\n devm_mdiobus_free+0x10/0x20\n devres_release_all+0xa0/0x100\n __device_release_driver+0x190/0x220\n device_release_driver_internal+0xac/0xb0\n device_links_unbind_consumers+0xd4/0x100\n __device_release_driver+0x4c/0x220\n device_release_driver_internal+0xac/0xb0\n device_links_unbind_consumers+0xd4/0x100\n __device_release_driver+0x94/0x220\n device_release_driver+0x28/0x40\n bus_remove_device+0x118/0x124\n device_del+0x174/0x420\n fsl_mc_device_remove+0x24/0x40\n __fsl_mc_device_remove+0xc/0x20\n device_for_each_child+0x58/0xa0\n dprc_remove+0x90/0xb0\n fsl_mc_driver_remove+0x20/0x5c\n __device_release_driver+0x21c/0x220\n device_release_driver+0x28/0x40\n bus_remove_device+0x118/0x124\n device_del+0x174/0x420\n fsl_mc_bus_remove+0x80/0x100\n fsl_mc_bus_shutdown+0xc/0x1c\n platform_shutdown+0x20/0x30\n device_shutdown+0x154/0x330\n kernel_power_off+0x34/0x6c\n __do_sys_reboot+0x15c/0x250\n __arm64_sys_reboot+0x20/0x30\n invoke_syscall.constprop.0+0x4c/0xe0\n do_el0_svc+0x4c/0x150\n el0_svc+0x24/0xb0\n el0t_64_sync_handler+0xa8/0xb0\n el0t_64_sync+0x178/0x17c\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 Marvell driver already has a good structure for mdiobus removal, so\njust plug in mdiobus_free and get rid of devres.",
"id": "GHSA-j4rr-5cq7-mpjq",
"modified": "2024-07-16T12:30:40Z",
"published": "2024-07-16T12:30:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-48818"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1b451c3994a2d322f8e55032c62c8b47b7d95900"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8b626d45127d6f5ada7d815b83cfdc09e8cb1394"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8ccebe77df6e0d88c72ba5e69cf1835927e53b6c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f53a2ce893b2c7884ef94471f170839170a4eba0"
}
],
"schema_version": "1.4.0",
"severity": []
}
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