CVE-2024-35809

CVE Details

Release Date:

2024-05-17

Description

In the Linux kernel, the following vulnerability has been resolved:\nPCI/PM: Drain runtime-idle callbacks before driver removal\nA race condition between the .runtime_idle() callback and the .remove()\ncallback in the rtsx_pcr PCI driver leads to a kernel crash due to an\nunhandled page fault [1].\nThe problem is that rtsx_pci_runtime_idle() is not expected to be running\nafter pm_runtime_get_sync() has been called, but the latter doesn't really\nguarantee that. It only guarantees that the suspend and resume callbacks\nwill not be running when it returns.\nHowever, if a .runtime_idle() callback is already running when\npm_runtime_get_sync() is called, the latter will notice that the runtime PM\nstatus of the device is RPM_ACTIVE and it will return right away without\nwaiting for the former to complete. In fact, it cannot wait for\n.runtime_idle() to complete because it may be called from that callback (it\narguably does not make much sense to do that, but it is not strictly\nprohibited).\nThus in general, whoever is providing a .runtime_idle() callback needs\nto protect it from running in parallel with whatever code runs after\npm_runtime_get_sync(). [Note that .runtime_idle() will not start after\npm_runtime_get_sync() has returned, but it may continue running then if it\nhas started earlier.]\nOne way to address that race condition is to call pm_runtime_barrier()\nafter pm_runtime_get_sync() (not before it, because a nonzero value of the\nruntime PM usage counter is necessary to prevent runtime PM callbacks from\nbeing invoked) to wait for the .runtime_idle() callback to complete should\nit be running at that point. A suitable place for doing that is in\npci_device_remove() which calls pm_runtime_get_sync() before removing the\ndriver, so it may as well call pm_runtime_barrier() subsequently, which\nwill prevent the race in question from occurring, not just in the rtsx_pcr\ndriver, but in any PCI drivers providing .runtime_idle() callbacks.

See more information about CVE-2024-35809 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	5.5	CVSS Vector:	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector:	Local network	Attack Complexity:	Low
Privileges Required:	Low	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 8 (kernel)	ELSA-2024-7000	2024-09-24
Oracle Linux version 9 (kernel)	ELSA-2024-9315	2024-11-14