{"id":"CVE-2026-99160","kind":"vulnerability","aliases":["CVE-2026-99160"],"related":[],"title":"Linux kernel: reading ring-buffer metadata for offline CPU crashes","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Do not show buffer_meta for CPUs without a buffer\n\nThe per_cpu/cpuN/buffer_meta files are created for every possible CPU,\nbut buffer->buffers[cpu] is only allocated once that CPU comes online.\nReading the file of a CPU that never came online dereferences a NULL\ncpu_buffer in rbm_start().\n\nFail the open with -ENODEV when the CPU has no buffer, as the other\nper CPU ring buffer interfaces do.","summary":"The Linux kernel's ring buffer tracing interface creates a buffer_meta file for every possible CPU, including CPUs that never came online. Reading one of those files dereferences a NULL buffer pointer, which crashes the kernel.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","kernel","linux"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-10-28T11:17:36+00:00","first_seen_at":"2026-10-28T11:32:36+00:00","triaged_at":"2026-10-28T11:35:45+00:00","updated_at":"2026-10-28T11:35:45+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-10-28T11:35:45Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Linux kernel: reading ring-buffer metadata for offline CPU crashes","impact":"low","summary":"The Linux kernel's ring buffer tracing interface creates a buffer_meta file for every possible CPU, including CPUs that never came online. Reading one of those files dereferences a NULL buffer pointer, which crashes the kernel.","category":"infrastructure","nicknames":[],"who_cares":["linux","kernel"],"confidence":0.5,"needs_auth":"unknown","worst_case":"kernel crash from a read of an offline CPU's buffer_meta file","analyst_note":"Check the kernel.org fix commit and stable backports to confirm affected kernel versions and whether a local user without root can read the file.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":[],"who_is_affected":"unknown","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"low"},"cost_usd":0.000514,"input_tokens":3406,"output_tokens":347,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-99160':14A,17A 'alloc':97C 'buffer':6A,26B,31B,52B,70C,74C,80C,92C,93C,117C,131C,138C 'came':42B,111C 'come':101C 'cpu':10A,37B,90C,94C,100C,108C,116C,128C,136C 'cpu/cpun/buffer_meta':83C 'cpus':39B,77C 'crash':11A,55B 'creat':29B,86C 'cve':12A,15A 'derefer':49B,113C 'enodev':125C 'everi':35B,88C 'fail':121C 'file':33B,48B,84C,105C 'follow':63C 'includ':38B 'infrastructur':18B 'interfac':28B,139C 'kernel':2A,19B,23B,57B,61C 'linux':1A,20B,22B,60C 'meta':32B,75C 'metadata':7A 'never':41B,110C 'null':51B,115C 'offlin':9A 'one':45B 'onlin':43B,102C,112C 'open':123C 'per':82C,135C 'pointer':53B 'possibl':36B,89C 'rbm':119C 'read':3A,44B,103C 'resolv':67C 'ring':5A,25B,69C,137C 'ring-buff':4A,68C 'show':73C 'start':120C 'trace':27B 'vulner':64C 'without':78C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-28T11:17:36+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-99160","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99160","severity":null,"published_at":"2026-10-28T11:17:36+00:00","modified_at":"2026-10-28T11:17:36+00:00","first_seen_at":"2026-10-28T11:32:36+00:00","fetched_at":"2026-10-28T11:32:36+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"}