{"id":"CVE-2026-98652","kind":"vulnerability","aliases":["CVE-2026-98652"],"related":[],"title":"Linux kernel KVM s390: missing SRCU lock in IRQ state setting","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Add missing srcu in kvm_s390_set_irq_state()\n\nLike kvm_s390_inject_vcpu(), kvm_s390_set_irq_state() also needs the\nkvm->srcu or the slots lock when performing the Store status operation.\n\nFix by taking kvm->srcu in kvm_s390_set_irq_state().","summary":"The Linux kernel's KVM on IBM s390 did not hold the kvm->srcu lock while performing a store status operation in kvm_s390_set_irq_state(), a locking gap that can leave memory accessed without proper protection. The fix takes kvm->srcu in that function; the sources give no further impact detail.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","kvm","linux-kernel","mainframe","s390"],"not_affected_if":["non-s390-architecture"],"how_to_check":null,"fix":"- Update the Linux kernel to a release that includes the upstream commit adding kvm->srcu to kvm_s390_set_irq_state() (version unknown from sources)","status":"open","published_at":"2026-10-18T16:17:18+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","triaged_at":"2026-10-25T05:19:38+00:00","updated_at":"2026-10-25T05:19:38+00:00","category":"infrastructure","confidence":0.35,"triage":{"at":"2026-10-25T05:19:38Z","model":"claude-haiku-5-5","output":{"fix":"- Update the Linux kernel to a release that includes the upstream commit adding kvm->srcu to kvm_s390_set_irq_state() (version unknown from sources)","reach":"unknown","title":"Linux kernel KVM s390: missing SRCU lock in IRQ state setting","impact":"low","summary":"The Linux kernel's KVM on IBM s390 did not hold the kvm->srcu lock while performing a store status operation in kvm_s390_set_irq_state(), a locking gap that can leave memory accessed without proper protection. The fix takes kvm->srcu in that function; the sources give no further impact detail.","category":"infrastructure","nicknames":[],"who_cares":["linux-kernel","kvm","s390","mainframe"],"confidence":0.35,"needs_auth":"unknown","worst_case":"unknown; the sources describe only a missing lock","analyst_note":"Check the kernel.org stable commit for kvm_s390_set_irq_state to confirm the exploitable impact, affected kernel version ranges and the fixed stable release.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["non-s390-architecture"],"who_is_affected":"Only hosts running the Linux kernel KVM hypervisor on IBM s390 (mainframe) hardware are relevant. Systems on other architectures are not affected by this s390-specific change.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000594,"input_tokens":3352,"output_tokens":518,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-98652':14A,17A 'access':59B 'add':90C 'also':109C 'cve':12A,15A 'detail':77B 'fix':64B,124C 'follow':83C 'function':70B 'gap':54B 'give':73B 'hold':35B 'ibm':31B 'impact':76B 'infrastructur':18B 'inject':102C 'irq':9A,50B,97C,107C,133C 'kernel':2A,22B,27B,81C 'kvm':3A,19B,29B,37B,47B,66B,88C,94C,100C,104C,112C,127C,130C 'leav':57B 'like':99C 'linux':1A,21B,26B,80C 'linux-kernel':20B 'lock':7A,39B,53B,117C 'mainfram':23B 'memori':58B 'miss':5A,91C 'need':110C 'oper':45B,123C 'perform':41B,119C 'proper':61B 'protect':62B 'resolv':87C 's390':4A,24B,32B,48B,89C,95C,101C,105C,131C 'set':11A,49B,96C,106C,132C 'slot':116C 'sourc':72B 'srcu':6A,38B,67B,92C,113C,128C 'state':10A,51B,98C,108C,134C 'status':44B,122C 'store':43B,121C 'take':65B,126C 'vcpu':103C 'vulner':84C 'without':60B","nicknames":[],"mitigations":[],"who_affected":"Only hosts running the Linux kernel KVM hypervisor on IBM s390 (mainframe) hardware are relevant. Systems on other architectures are not affected by this s390-specific change.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-18T16:17:18+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-98652","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98652","severity":null,"published_at":"2026-10-18T16:17:18+00:00","modified_at":"2026-10-19T10:19:29+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","fetched_at":"2026-10-23T22:28:56+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}