{"api_version":"1","generated_at":"2026-10-01T07:41:54+00:00","cve":"CVE-2026-97925","urls":{"html":"https://cve.report/CVE-2026-97925","api":"https://cve.report/api/cve/CVE-2026-97925.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-97925","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-97925"},"summary":{"title":"tick/broadcast: Plug clockevents replacement race","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntick/broadcast: Plug clockevents replacement race\n\n朱恺乾 reported and decoded the following race condition when a broadcast\ndevice is replaced:\n\nCPUA\t\t\t\t\tCPUB\n __tick_broadcast_oneshot_control()\n   bc = tick_broadcast_device.evtdev;\n\t\t\t\t\ttick_install_broadcast_device(dev)\n        \t\t\t\tclockevents_exchange_device(cur, dev)\n\t\t\t\t\t   shutdown(cur);\n\t\t\t\t\t   detach(cur);\n\t\t\t\t\t   cur->handler = noop;\n\t\t\t\t\t   tick_broadcast_device.evtdev = dev;\n\n  tick_broadcast_set_event(bc, next_event); <- FAIL: arms a detached device.\n\nIf the original broadcast device has a restricted interrupt affinity mask\nand the last CPU in that mask goes offline then the BUG() in\ntick_cleanup_dead_cpu() triggers because the clockevent device is not in\ndetached state.\n\nThe reason for this is that tick_install_broadcast_device() is not\nserialized vs. tick broadcast operations.\n\nThe obvious cure is to serialize tick_install_broadcast_device() with\ntick_broadcast_lock against a concurrent tick broadcast operation.\n\nThat requires to split clockevents_exchange_device() into two parts, one\nwhich does the exchange, shutdown and detach operation and the other which\ndrops the module reference count. This is required because the module\nreference cannot be dropped while holding tick_broadcast_lock.\n\nLet clockevents_exchange_device() do both operations as before, but let the\nbroadcast device code take the two step approach and do the device\nexchange under tick_broadcast_lock and drop the module reference count\nafter releasing it.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:19","updated_at":"2026-09-25 11:17:19"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/292b7a8ed84032cfdfc9076a690360f7d3f640d4","name":"https://git.kernel.org/stable/c/292b7a8ed84032cfdfc9076a690360f7d3f640d4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3525b94b2f258e0b99d1ee5a82a80b51bc1cc818","name":"https://git.kernel.org/stable/c/3525b94b2f258e0b99d1ee5a82a80b51bc1cc818","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3da55616db2b6b7d9caa3b7ff1e8983224e0ed52","name":"https://git.kernel.org/stable/c/3da55616db2b6b7d9caa3b7ff1e8983224e0ed52","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/113a9796effe3376d2ec5aabcca1fef4fef4cd62","name":"https://git.kernel.org/stable/c/113a9796effe3376d2ec5aabcca1fef4fef4cd62","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97925","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97925","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 3da55616db2b6b7d9caa3b7ff1e8983224e0ed52 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 3525b94b2f258e0b99d1ee5a82a80b51bc1cc818 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 292b7a8ed84032cfdfc9076a690360f7d3f640d4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98 113a9796effe3376d2ec5aabcca1fef4fef4cd62 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.21","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.21 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.7 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"97925","cve":"CVE-2026-97925","epss":"0.002000000","percentile":"0.088200000","score_date":"2026-09-27","updated_at":"2026-09-28 00:02:24"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["kernel/time/clockevents.c","kernel/time/tick-broadcast.c","kernel/time/tick-internal.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"3da55616db2b6b7d9caa3b7ff1e8983224e0ed52","status":"affected","version":"f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98","versionType":"git"},{"lessThan":"3525b94b2f258e0b99d1ee5a82a80b51bc1cc818","status":"affected","version":"f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98","versionType":"git"},{"lessThan":"292b7a8ed84032cfdfc9076a690360f7d3f640d4","status":"affected","version":"f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98","versionType":"git"},{"lessThan":"113a9796effe3376d2ec5aabcca1fef4fef4cd62","status":"affected","version":"f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["kernel/time/clockevents.c","kernel/time/tick-broadcast.c","kernel/time/tick-internal.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.21"},{"lessThan":"2.6.21","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.111","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.53","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.111","versionStartIncluding":"2.6.21","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"2.6.21","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"2.6.21","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc3","versionStartIncluding":"2.6.21","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntick/broadcast: Plug clockevents replacement race\n\n朱恺乾 reported and decoded the following race condition when a broadcast\ndevice is replaced:\n\nCPUA\t\t\t\t\tCPUB\n __tick_broadcast_oneshot_control()\n   bc = tick_broadcast_device.evtdev;\n\t\t\t\t\ttick_install_broadcast_device(dev)\n        \t\t\t\tclockevents_exchange_device(cur, dev)\n\t\t\t\t\t   shutdown(cur);\n\t\t\t\t\t   detach(cur);\n\t\t\t\t\t   cur->handler = noop;\n\t\t\t\t\t   tick_broadcast_device.evtdev = dev;\n\n  tick_broadcast_set_event(bc, next_event); <- FAIL: arms a detached device.\n\nIf the original broadcast device has a restricted interrupt affinity mask\nand the last CPU in that mask goes offline then the BUG() in\ntick_cleanup_dead_cpu() triggers because the clockevent device is not in\ndetached state.\n\nThe reason for this is that tick_install_broadcast_device() is not\nserialized vs. tick broadcast operations.\n\nThe obvious cure is to serialize tick_install_broadcast_device() with\ntick_broadcast_lock against a concurrent tick broadcast operation.\n\nThat requires to split clockevents_exchange_device() into two parts, one\nwhich does the exchange, shutdown and detach operation and the other which\ndrops the module reference count. This is required because the module\nreference cannot be dropped while holding tick_broadcast_lock.\n\nLet clockevents_exchange_device() do both operations as before, but let the\nbroadcast device code take the two step approach and do the device\nexchange under tick_broadcast_lock and drop the module reference count\nafter releasing it."}],"providerMetadata":{"dateUpdated":"2026-09-25T10:22:43.552Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/3da55616db2b6b7d9caa3b7ff1e8983224e0ed52"},{"url":"https://git.kernel.org/stable/c/3525b94b2f258e0b99d1ee5a82a80b51bc1cc818"},{"url":"https://git.kernel.org/stable/c/292b7a8ed84032cfdfc9076a690360f7d3f640d4"},{"url":"https://git.kernel.org/stable/c/113a9796effe3376d2ec5aabcca1fef4fef4cd62"}],"title":"tick/broadcast: Plug clockevents replacement race","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-97925","datePublished":"2026-09-25T10:22:43.552Z","dateReserved":"2026-09-25T10:18:58.202Z","dateUpdated":"2026-09-25T10:22:43.552Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:19","lastModifiedDate":"2026-09-25 11:17:19","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"97925","Ordinal":"1","Title":"tick/broadcast: Plug clockevents replacement race","CVE":"CVE-2026-97925","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"97925","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ntick/broadcast: Plug clockevents replacement race\n\n朱恺乾 reported and decoded the following race condition when a broadcast\ndevice is replaced:\n\nCPUA\t\t\t\t\tCPUB\n __tick_broadcast_oneshot_control()\n   bc = tick_broadcast_device.evtdev;\n\t\t\t\t\ttick_install_broadcast_device(dev)\n        \t\t\t\tclockevents_exchange_device(cur, dev)\n\t\t\t\t\t   shutdown(cur);\n\t\t\t\t\t   detach(cur);\n\t\t\t\t\t   cur->handler = noop;\n\t\t\t\t\t   tick_broadcast_device.evtdev = dev;\n\n  tick_broadcast_set_event(bc, next_event); <- FAIL: arms a detached device.\n\nIf the original broadcast device has a restricted interrupt affinity mask\nand the last CPU in that mask goes offline then the BUG() in\ntick_cleanup_dead_cpu() triggers because the clockevent device is not in\ndetached state.\n\nThe reason for this is that tick_install_broadcast_device() is not\nserialized vs. tick broadcast operations.\n\nThe obvious cure is to serialize tick_install_broadcast_device() with\ntick_broadcast_lock against a concurrent tick broadcast operation.\n\nThat requires to split clockevents_exchange_device() into two parts, one\nwhich does the exchange, shutdown and detach operation and the other which\ndrops the module reference count. This is required because the module\nreference cannot be dropped while holding tick_broadcast_lock.\n\nLet clockevents_exchange_device() do both operations as before, but let the\nbroadcast device code take the two step approach and do the device\nexchange under tick_broadcast_lock and drop the module reference count\nafter releasing it.","Type":"Description","Title":"tick/broadcast: Plug clockevents replacement race"}]}}}