{"api_version":"1","generated_at":"2026-07-24T21:51:54+00:00","cve":"CVE-2026-64250","urls":{"html":"https://cve.report/CVE-2026-64250","api":"https://cve.report/api/cve/CVE-2026-64250.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64250","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64250"},"summary":{"title":"LoongArch: Report dying CPU to RCU in stop_this_cpu()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Report dying CPU to RCU in stop_this_cpu()\n\nThis is a port of MIPS commit 9f3f3bdc6d9dac1 (\"MIPS: smp: report dying\nCPU to RCU in stop_this_cpu()\"). smp_send_stop() parks all secondary\nCPUs in stop_this_cpu(). And the function marks the CPU offline for the\nscheduler via set_cpu_online(false) but never informs RCU, so RCU keeps\nexpecting a quiescent state from CPUs that are now spinning forever with\ninterrupts disabled.\n\nAs long as nothing waits for an RCU grace period after smp_send_stop()\nthis is harmless, which is why it went unnoticed. However, since commit\n91840be8f710370 (\"irq_work: Fix use-after-free in irq_work_single() on\nPREEMPT_RT\"), irq_work_sync() calls synchronize_rcu() on architectures\nwithout an irq_work self-IPI, i.e. where arch_irq_work_has_interrupt()\nreturns false. Any irq_work_sync() issued in the reboot/shutdown/halt\npath after smp_send_stop() then blocks on a grace period that can never\ncomplete, hanging the reboot:\n\n  WARNING: CPU: 0 PID: 15 at kernel/irq_work.c:144 irq_work_queue_on\n  ...\n  rcu: INFO: rcu_sched detected stalls on CPUs/tasks:\n  rcu: Offline CPU 1 blocking current GP.\n  rcu: Offline CPU 2 blocking current GP.\n  rcu: Offline CPU 3 blocking current GP.\n\nThis issue needs some hacks to reproduce, and it was not noticed on\nLoongArch because arch_irq_work_has_interrupt() usually returns true.\n\nCall rcutree_report_cpu_dead() once interrupts are disabled, mirroring\nthe generic CPU-hotplug offline path, so RCU stops waiting on the parked\nCPUs and grace periods can still complete. LoongArch shuts down all CPUs\nhere without going through the CPU-hotplug mechanism, so this report is\nnot otherwise issued.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-24 16:16:54","updated_at":"2026-07-24 16:16:54"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/0833b2b84c2fc1387f8165f0cbf6a02d67f647a5","name":"https://git.kernel.org/stable/c/0833b2b84c2fc1387f8165f0cbf6a02d67f647a5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/90e254f18b8c224460082329dd5c42fd30995c2f","name":"https://git.kernel.org/stable/c/90e254f18b8c224460082329dd5c42fd30995c2f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/262dadc619e69ebeb97affd334cd1078a9704e98","name":"https://git.kernel.org/stable/c/262dadc619e69ebeb97affd334cd1078a9704e98","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f2539c56c74691e7a88af6372ba2b48c06ed2fe4","name":"https://git.kernel.org/stable/c/f2539c56c74691e7a88af6372ba2b48c06ed2fe4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a0269e928728f970c782319fee53d92d4ea4e512","name":"https://git.kernel.org/stable/c/a0269e928728f970c782319fee53d92d4ea4e512","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1fa22de588a65880d6fe54c38c87fffe7d519f60","name":"https://git.kernel.org/stable/c/1fa22de588a65880d6fe54c38c87fffe7d519f60","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64250","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64250","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2dc79362302922cb18f35e262712b5e58de65442 262dadc619e69ebeb97affd334cd1078a9704e98 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected eef4f71b46a9929ac33e968538c9dd5d96a02460 1fa22de588a65880d6fe54c38c87fffe7d519f60 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 684a78183c54c23e70d1cba320f7fc184604210b a0269e928728f970c782319fee53d92d4ea4e512 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 18c0456ea2615b1a743a6db739c74411c3b42bc6 90e254f18b8c224460082329dd5c42fd30995c2f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 91840be8f710370607f949a627e070896faeddb8 0833b2b84c2fc1387f8165f0cbf6a02d67f647a5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 91840be8f710370607f949a627e070896faeddb8 f2539c56c74691e7a88af6372ba2b48c06ed2fe4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 81b582784518196eff1050212a046bc29d3a05dd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.1.175 6.1.178 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6.142 6.6.145 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.12.92 6.12.95 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.18.34 6.18.38 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.0.11 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.95 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.38 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.3 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/loongarch/kernel/smp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"262dadc619e69ebeb97affd334cd1078a9704e98","status":"affected","version":"2dc79362302922cb18f35e262712b5e58de65442","versionType":"git"},{"lessThan":"1fa22de588a65880d6fe54c38c87fffe7d519f60","status":"affected","version":"eef4f71b46a9929ac33e968538c9dd5d96a02460","versionType":"git"},{"lessThan":"a0269e928728f970c782319fee53d92d4ea4e512","status":"affected","version":"684a78183c54c23e70d1cba320f7fc184604210b","versionType":"git"},{"lessThan":"90e254f18b8c224460082329dd5c42fd30995c2f","status":"affected","version":"18c0456ea2615b1a743a6db739c74411c3b42bc6","versionType":"git"},{"lessThan":"0833b2b84c2fc1387f8165f0cbf6a02d67f647a5","status":"affected","version":"91840be8f710370607f949a627e070896faeddb8","versionType":"git"},{"lessThan":"f2539c56c74691e7a88af6372ba2b48c06ed2fe4","status":"affected","version":"91840be8f710370607f949a627e070896faeddb8","versionType":"git"},{"status":"affected","version":"81b582784518196eff1050212a046bc29d3a05dd","versionType":"git"},{"lessThan":"6.1.178","status":"affected","version":"6.1.175","versionType":"semver"},{"lessThan":"6.6.145","status":"affected","version":"6.6.142","versionType":"semver"},{"lessThan":"6.12.95","status":"affected","version":"6.12.92","versionType":"semver"},{"lessThan":"6.18.38","status":"affected","version":"6.18.34","versionType":"semver"},{"lessThan":"7.1","status":"affected","version":"7.0.11","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/loongarch/kernel/smp.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.95","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.38","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"6.1.175","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"6.6.142","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.95","versionStartIncluding":"6.12.92","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.38","versionStartIncluding":"6.18.34","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.3","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Report dying CPU to RCU in stop_this_cpu()\n\nThis is a port of MIPS commit 9f3f3bdc6d9dac1 (\"MIPS: smp: report dying\nCPU to RCU in stop_this_cpu()\"). smp_send_stop() parks all secondary\nCPUs in stop_this_cpu(). And the function marks the CPU offline for the\nscheduler via set_cpu_online(false) but never informs RCU, so RCU keeps\nexpecting a quiescent state from CPUs that are now spinning forever with\ninterrupts disabled.\n\nAs long as nothing waits for an RCU grace period after smp_send_stop()\nthis is harmless, which is why it went unnoticed. However, since commit\n91840be8f710370 (\"irq_work: Fix use-after-free in irq_work_single() on\nPREEMPT_RT\"), irq_work_sync() calls synchronize_rcu() on architectures\nwithout an irq_work self-IPI, i.e. where arch_irq_work_has_interrupt()\nreturns false. Any irq_work_sync() issued in the reboot/shutdown/halt\npath after smp_send_stop() then blocks on a grace period that can never\ncomplete, hanging the reboot:\n\n  WARNING: CPU: 0 PID: 15 at kernel/irq_work.c:144 irq_work_queue_on\n  ...\n  rcu: INFO: rcu_sched detected stalls on CPUs/tasks:\n  rcu: Offline CPU 1 blocking current GP.\n  rcu: Offline CPU 2 blocking current GP.\n  rcu: Offline CPU 3 blocking current GP.\n\nThis issue needs some hacks to reproduce, and it was not noticed on\nLoongArch because arch_irq_work_has_interrupt() usually returns true.\n\nCall rcutree_report_cpu_dead() once interrupts are disabled, mirroring\nthe generic CPU-hotplug offline path, so RCU stops waiting on the parked\nCPUs and grace periods can still complete. LoongArch shuts down all CPUs\nhere without going through the CPU-hotplug mechanism, so this report is\nnot otherwise issued."}],"providerMetadata":{"dateUpdated":"2026-07-24T15:31:17.021Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/262dadc619e69ebeb97affd334cd1078a9704e98"},{"url":"https://git.kernel.org/stable/c/1fa22de588a65880d6fe54c38c87fffe7d519f60"},{"url":"https://git.kernel.org/stable/c/a0269e928728f970c782319fee53d92d4ea4e512"},{"url":"https://git.kernel.org/stable/c/90e254f18b8c224460082329dd5c42fd30995c2f"},{"url":"https://git.kernel.org/stable/c/0833b2b84c2fc1387f8165f0cbf6a02d67f647a5"},{"url":"https://git.kernel.org/stable/c/f2539c56c74691e7a88af6372ba2b48c06ed2fe4"}],"title":"LoongArch: Report dying CPU to RCU in stop_this_cpu()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64250","datePublished":"2026-07-24T15:31:17.021Z","dateReserved":"2026-07-19T15:36:31.773Z","dateUpdated":"2026-07-24T15:31:17.021Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-24 16:16:54","lastModifiedDate":"2026-07-24 16:16:54","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64250","Ordinal":"1","Title":"LoongArch: Report dying CPU to RCU in stop_this_cpu()","CVE":"CVE-2026-64250","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64250","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Report dying CPU to RCU in stop_this_cpu()\n\nThis is a port of MIPS commit 9f3f3bdc6d9dac1 (\"MIPS: smp: report dying\nCPU to RCU in stop_this_cpu()\"). smp_send_stop() parks all secondary\nCPUs in stop_this_cpu(). And the function marks the CPU offline for the\nscheduler via set_cpu_online(false) but never informs RCU, so RCU keeps\nexpecting a quiescent state from CPUs that are now spinning forever with\ninterrupts disabled.\n\nAs long as nothing waits for an RCU grace period after smp_send_stop()\nthis is harmless, which is why it went unnoticed. However, since commit\n91840be8f710370 (\"irq_work: Fix use-after-free in irq_work_single() on\nPREEMPT_RT\"), irq_work_sync() calls synchronize_rcu() on architectures\nwithout an irq_work self-IPI, i.e. where arch_irq_work_has_interrupt()\nreturns false. Any irq_work_sync() issued in the reboot/shutdown/halt\npath after smp_send_stop() then blocks on a grace period that can never\ncomplete, hanging the reboot:\n\n  WARNING: CPU: 0 PID: 15 at kernel/irq_work.c:144 irq_work_queue_on\n  ...\n  rcu: INFO: rcu_sched detected stalls on CPUs/tasks:\n  rcu: Offline CPU 1 blocking current GP.\n  rcu: Offline CPU 2 blocking current GP.\n  rcu: Offline CPU 3 blocking current GP.\n\nThis issue needs some hacks to reproduce, and it was not noticed on\nLoongArch because arch_irq_work_has_interrupt() usually returns true.\n\nCall rcutree_report_cpu_dead() once interrupts are disabled, mirroring\nthe generic CPU-hotplug offline path, so RCU stops waiting on the parked\nCPUs and grace periods can still complete. LoongArch shuts down all CPUs\nhere without going through the CPU-hotplug mechanism, so this report is\nnot otherwise issued.","Type":"Description","Title":"LoongArch: Report dying CPU to RCU in stop_this_cpu()"}]}}}