{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49884","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-05-01T14:05:17.241Z","datePublished":"2025-05-01T14:10:30.589Z","dateUpdated":"2026-08-05T08:56:33.067Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T08:56:33.067Z"},"descriptions":[{"lang":"en","value":"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()'s\nability to re-initialize the cache's 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(&gpc->lock, ...)      |\n                                          | kvm_gfn_to_pfn_cache_init\n                                          |  rwlock_init(&gpc->lock)\n  read_unlock_irqrestore(&gpc->lock, ...) |\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]"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is triggered via KVM ioctls (KVM_XEN_HVM_EVTCHN_SEND racing with KVM_XEN_HVM_SET_ATTR / gpc activate) on a VM fd from /dev/kvm, which requires local process access.\nAC:L - The attacker fully controls both sides of the race by running concurrent threads that issue EVTCHN_SEND while deactivating/reactivating the shared_info gfn_to_pfn_cache, so success does not depend on external conditions.\nPR:L - Exploitation needs only the ability to open /dev/kvm and create a VM (typically kvm-group membership); no CAP_SYS_ADMIN or real root is required along the ioctl path.\nUI:N - The attacker performs the ioctls directly against their own VM; no action by another user is required.\nS:U - The clear attack is host userspace with KVM access corrupting host kernel lock state, which is privilege escalation within the same security authority rather than a guest-to-host escape.\nC:H - Re-initializing an rwlock while it is held corrupts kernel synchronization state and can yield use-after-free / memory-corruption primitives (as related gpc races explicitly warn), enabling arbitrary confidentiality impact.\nI:H - Corrupted gpc locks and the resulting memory corruption can be leveraged for arbitrary kernel writes or control-flow hijacking, not merely a benign state inconsistency.\nA:H - Unlocking or using a re-initialized rwlock reliably causes kernel oops/BUG, hangs, or panic; the related inactive-cache race also demonstrates a direct NULL deref crash path."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/kvm/x86.c","arch/x86/kvm/xen.c","include/linux/kvm_host.h","virt/kvm/pfncache.c"],"versions":[{"version":"982ed0de4753ed6e71dbd40f82a5a066baf133ed","lessThan":"61242001d6c9c253df7645dab090842d8da08764","status":"affected","versionType":"git"},{"version":"982ed0de4753ed6e71dbd40f82a5a066baf133ed","lessThan":"52491a38b2c2411f3f0229dc6ad610349c704a41","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/kvm/x86.c","arch/x86/kvm/xen.c","include/linux/kvm_host.h","virt/kvm/pfncache.c"],"versions":[{"version":"5.17","status":"affected"},{"version":"0","lessThan":"5.17","status":"unaffected","versionType":"semver"},{"version":"6.0.8","lessThanOrEqual":"6.0.*","status":"unaffected","versionType":"semver"},{"version":"6.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.0.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/61242001d6c9c253df7645dab090842d8da08764"},{"url":"https://git.kernel.org/stable/c/52491a38b2c2411f3f0229dc6ad610349c704a41"}],"title":"KVM: Initialize gfn_to_pfn_cache locks in dedicated helper","x_generator":{"engine":"bippy-1.2.0"}}}}