CVE-2022-49884

KVM: Initialize gfn_to_pfn_cache locks in dedicated helper

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: Initialize gfn_to_pfn_cache locks in dedicated helper Move the gfn_to_pfn_cache lock initialization to another helper and call the new helper during VM/vCPU creation. There are race conditions possible due to kvm_gfn_to_pfn_cache_init()'s ability to re-initialize the cache's locks. For example: a race between ioctl(KVM_XEN_HVM_EVTCHN_SEND) and kvm_gfn_to_pfn_cache_init() leads to a corrupted shinfo gpc lock. (thread 1) | (thread 2) | kvm_xen_set_evtchn_fast | read_lock_irqsave(&gpc->lock, ...) | | kvm_gfn_to_pfn_cache_init | rwlock_init(&gpc->lock) read_unlock_irqrestore(&gpc->lock, ...) | Rename "cache_init" and "cache_destroy" to activate+deactivate to avoid implying that the cache really is destroyed/freed. Note, there more races in the newly named kvm_gpc_activate() that will be addressed separately. [sean: call out that this is a bug fix]

N/A

CVSS

Severity:

EPSS 0.02%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/61242001d6c9c253df7645dab090842d8da08764
https://git.kernel.org/stable/c/52491a38b2c2411f3f0229dc6ad610349c704a41

Frequently Asked Questions

What is the severity of CVE-2022-49884?: CVE-2022-49884 has not yet been assigned a CVSS score.
How to fix CVE-2022-49884?: To fix CVE-2022-49884, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2022-49884 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2022-49884 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2022-49884?: CVE-2022-49884 affects Linux Linux, Linux Linux.

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