{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-46295", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.110Z", "datePublished": "2026-06-08T15:46:22.494Z", "dateUpdated": "2026-06-08T15:46:22.494Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-06-08T15:46:22.494Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty\n\nFall back to apic_find_highest_vector() when PID.ON is set but PIR\nturns out to be empty, to correctly report the highest pending interrupt\nfrom the existing IRR.\n\nIn a nested VM stress test, the following WARNING fires in\nvmx_check_nested_events() when kvm_cpu_has_interrupt() reports a pending\ninterrupt but the subsequent kvm_apic_has_interrupt() (which invokes\nvmx_sync_pir_to_irr() again) returns -1:\n\n WARNING: CPU: 99 PID: 57767 at arch/x86/kvm/vmx/nested.c:4449 vmx_check_nested_events+0x6bf/0x6e0 [kvm_intel]\n Call Trace:\n kvm_check_and_inject_events\n vcpu_enter_guest.constprop.0\n vcpu_run\n kvm_arch_vcpu_ioctl_run\n kvm_vcpu_ioctl\n __x64_sys_ioctl\n do_syscall_64\n entry_SYSCALL_64_after_hwframe\n\nThe root cause is a race between vmx_sync_pir_to_irr() on the target vCPU\nand __vmx_deliver_posted_interrupt() on a sender vCPU. The sender\nperforms two individually-atomic operations that are not a single\ntransaction:\n\n 1. pi_test_and_set_pir(vector) -- sets the PIR bit\n 2. pi_test_and_set_on() -- sets PID.ON\n\nThe following interleaving triggers the bug:\n\n Sender vCPU (IPI): Target vCPU (1st sync_pir_to_irr):\n B1: set PIR[vector]\n A1: pi_clear_on()\n A2: pi_harvest_pir() -> sees B1 bit\n A3: xchg() -> consumes bit, PIR=0\n (1st sync returns correct max_irr)\n B2: set PID.ON = 1\n\n Target vCPU (2nd sync_pir_to_irr):\n C1: pi_test_on() -> TRUE (from B2)\n C2: pi_clear_on() -> ON=0\n C3: pi_harvest_pir() -> PIR empty\n C4: *max_irr = -1, early return\n IRR NOT SCANNED\n\nThe interrupt is not lost (it resides in the IRR from the first sync and\nis recovered on the next vcpu_enter_guest() iteration), but the incorrect\nmax_irr causes a spurious WARNING and a wasted L2 VM-Enter/VM-Exit cycle."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/lapic.c"], "versions": [{"version": "b41f8638b9d30fbe045b4ef83ff4136c56a57397", "lessThan": "bb1703949dcaa9a49c338dee075f659f4634214d", "status": "affected", "versionType": "git"}, {"version": "b41f8638b9d30fbe045b4ef83ff4136c56a57397", "lessThan": "4b6b06a8b12bfd95f9015074b1430c1480908073", "status": "affected", "versionType": "git"}, {"version": "b41f8638b9d30fbe045b4ef83ff4136c56a57397", "lessThan": "33fd0ccd2590b470b65adcca288615ad3b5e3e06", "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/lapic.c"], "versions": [{"version": "6.16", "status": "affected"}, {"version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.30", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.7", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1-rc3", "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": "6.16", "versionEndExcluding": "6.18.30"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.0.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.1-rc3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bb1703949dcaa9a49c338dee075f659f4634214d"}, {"url": "https://git.kernel.org/stable/c/4b6b06a8b12bfd95f9015074b1430c1480908073"}, {"url": "https://git.kernel.org/stable/c/33fd0ccd2590b470b65adcca288615ad3b5e3e06"}], "title": "KVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Do IRR scan in __kvm_apic_update_irr even if PIR is empty\n\nFall back to apic_find_highest_vector() when PID.ON is set but PIR\nturns out to be empty, to correctly report the highest pending interrupt\nfrom the existing IRR.\n\nIn a nested VM stress test, the following WARNING fires in\nvmx_check_nested_events() when kvm_cpu_has_interrupt() reports a pending\ninterrupt but the subsequent kvm_apic_has_interrupt() (which invokes\nvmx_sync_pir_to_irr() again) returns -1:\n\n WARNING: CPU: 99 PID: 57767 at arch/x86/kvm/vmx/nested.c:4449 vmx_check_nested_events+0x6bf/0x6e0 [kvm_intel]\n Call Trace:\n kvm_check_and_inject_events\n vcpu_enter_guest.constprop.0\n vcpu_run\n kvm_arch_vcpu_ioctl_run\n kvm_vcpu_ioctl\n __x64_sys_ioctl\n do_syscall_64\n entry_SYSCALL_64_after_hwframe\n\nThe root cause is a race between vmx_sync_pir_to_irr() on the target vCPU\nand __vmx_deliver_posted_interrupt() on a sender vCPU. The sender\nperforms two individually-atomic operations that are not a single\ntransaction:\n\n 1. pi_test_and_set_pir(vector) -- sets the PIR bit\n 2. pi_test_and_set_on() -- sets PID.ON\n\nThe following interleaving triggers the bug:\n\n Sender vCPU (IPI): Target vCPU (1st sync_pir_to_irr):\n B1: set PIR[vector]\n A1: pi_clear_on()\n A2: pi_harvest_pir() -> sees B1 bit\n A3: xchg() -> consumes bit, PIR=0\n (1st sync returns correct max_irr)\n B2: set PID.ON = 1\n\n Target vCPU (2nd sync_pir_to_irr):\n C1: pi_test_on() -> TRUE (from B2)\n C2: pi_clear_on() -> ON=0\n C3: pi_harvest_pir() -> PIR empty\n C4: *max_irr = -1, early return\n IRR NOT SCANNED\n\nThe interrupt is not lost (it resides in the IRR from the first sync and\nis recovered on the next vcpu_enter_guest() iteration), but the incorrect\nmax_irr causes a spurious WARNING and a wasted L2 VM-Enter/VM-Exit cycle."}], "id": "CVE-2026-46295", "lastModified": "2026-06-08T17:16:47.913", "metrics": {}, "published": "2026-06-08T17:16:47.913", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/33fd0ccd2590b470b65adcca288615ad3b5e3e06"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4b6b06a8b12bfd95f9015074b1430c1480908073"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bb1703949dcaa9a49c338dee075f659f4634214d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{}