ghsa-4m85-4x3p-6jmv
Vulnerability from github
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]
{
"affected": [],
"aliases": [
"CVE-2022-49884"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-01T15:16:13Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: Initialize gfn_to_pfn_cache locks in dedicated helper\n\nMove the gfn_to_pfn_cache lock initialization to another helper and\ncall the new helper during VM/vCPU creation. There are race\nconditions possible due to kvm_gfn_to_pfn_cache_init()\u0027s\nability to re-initialize the cache\u0027s locks.\n\nFor example: a race between ioctl(KVM_XEN_HVM_EVTCHN_SEND) and\nkvm_gfn_to_pfn_cache_init() leads to a corrupted shinfo gpc lock.\n\n (thread 1) | (thread 2)\n |\n kvm_xen_set_evtchn_fast |\n read_lock_irqsave(\u0026gpc-\u003elock, ...) |\n | kvm_gfn_to_pfn_cache_init\n | rwlock_init(\u0026gpc-\u003elock)\n read_unlock_irqrestore(\u0026gpc-\u003elock, ...) |\n\nRename \"cache_init\" and \"cache_destroy\" to activate+deactivate to\navoid implying that the cache really is destroyed/freed.\n\nNote, there more races in the newly named kvm_gpc_activate() that will\nbe addressed separately.\n\n[sean: call out that this is a bug fix]",
"id": "GHSA-4m85-4x3p-6jmv",
"modified": "2025-05-01T15:31:51Z",
"published": "2025-05-01T15:31:51Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49884"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/52491a38b2c2411f3f0229dc6ad610349c704a41"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/61242001d6c9c253df7645dab090842d8da08764"
}
],
"schema_version": "1.4.0",
"severity": []
}
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- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
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- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.