{"api_version":"1","generated_at":"2026-04-23T04:11:41+00:00","cve":"CVE-2026-31481","urls":{"html":"https://cve.report/CVE-2026-31481","api":"https://cve.report/api/cve/CVE-2026-31481.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31481","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31481"},"summary":{"title":"tracing: Drain deferred trigger frees if kthread creation fails","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Drain deferred trigger frees if kthread creation fails\n\nBoot-time trigger registration can fail before the trigger-data cleanup\nkthread exists. Deferring those frees until late init is fine, but the\npost-boot fallback must still drain the deferred list if kthread\ncreation never succeeds.\n\nOtherwise, boot-deferred nodes can accumulate on\ntrigger_data_free_list, later frees fall back to synchronously freeing\nonly the current object, and the older queued entries are leaked\nforever.\n\nTo trigger this, add the following to the kernel command line:\n\n  trace_event=sched_switch trace_trigger=sched_switch.traceon,sched_switch.traceon\n\nThe second traceon trigger will fail and be freed. This triggers a NULL\npointer dereference and crashes the kernel.\n\nKeep the deferred boot-time behavior, but when kthread creation fails,\ndrain the whole queued list synchronously. Do the same in the late-init\ndrain path so queued entries are not stranded there either.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-22 14:16:45","updated_at":"2026-04-22 14:16:45"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/250ab25391edeeab8462b68be42e4904506c409c","name":"https://git.kernel.org/stable/c/250ab25391edeeab8462b68be42e4904506c409c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/771624b7884a83bb9f922ae64ee41a5f8b7576c9","name":"https://git.kernel.org/stable/c/771624b7884a83bb9f922ae64ee41a5f8b7576c9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31481","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31481","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 61d445af0a7c70018111919e47beaaee15653f2f 771624b7884a83bb9f922ae64ee41a5f8b7576c9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 61d445af0a7c70018111919e47beaaee15653f2f 250ab25391edeeab8462b68be42e4904506c409c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.19","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.11 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * 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":["kernel/trace/trace_events_trigger.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"771624b7884a83bb9f922ae64ee41a5f8b7576c9","status":"affected","version":"61d445af0a7c70018111919e47beaaee15653f2f","versionType":"git"},{"lessThan":"250ab25391edeeab8462b68be42e4904506c409c","status":"affected","version":"61d445af0a7c70018111919e47beaaee15653f2f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["kernel/trace/trace_events_trigger.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.19"},{"lessThan":"6.19","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.11","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.11","versionStartIncluding":"6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"6.19","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Drain deferred trigger frees if kthread creation fails\n\nBoot-time trigger registration can fail before the trigger-data cleanup\nkthread exists. Deferring those frees until late init is fine, but the\npost-boot fallback must still drain the deferred list if kthread\ncreation never succeeds.\n\nOtherwise, boot-deferred nodes can accumulate on\ntrigger_data_free_list, later frees fall back to synchronously freeing\nonly the current object, and the older queued entries are leaked\nforever.\n\nTo trigger this, add the following to the kernel command line:\n\n  trace_event=sched_switch trace_trigger=sched_switch.traceon,sched_switch.traceon\n\nThe second traceon trigger will fail and be freed. This triggers a NULL\npointer dereference and crashes the kernel.\n\nKeep the deferred boot-time behavior, but when kthread creation fails,\ndrain the whole queued list synchronously. Do the same in the late-init\ndrain path so queued entries are not stranded there either."}],"providerMetadata":{"dateUpdated":"2026-04-22T13:54:08.236Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/771624b7884a83bb9f922ae64ee41a5f8b7576c9"},{"url":"https://git.kernel.org/stable/c/250ab25391edeeab8462b68be42e4904506c409c"}],"title":"tracing: Drain deferred trigger frees if kthread creation fails","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31481","datePublished":"2026-04-22T13:54:08.236Z","dateReserved":"2026-03-09T15:48:24.100Z","dateUpdated":"2026-04-22T13:54:08.236Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-22 14:16:45","lastModifiedDate":"2026-04-22 14:16:45","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31481","Ordinal":"1","Title":"tracing: Drain deferred trigger frees if kthread creation fails","CVE":"CVE-2026-31481","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31481","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Drain deferred trigger frees if kthread creation fails\n\nBoot-time trigger registration can fail before the trigger-data cleanup\nkthread exists. Deferring those frees until late init is fine, but the\npost-boot fallback must still drain the deferred list if kthread\ncreation never succeeds.\n\nOtherwise, boot-deferred nodes can accumulate on\ntrigger_data_free_list, later frees fall back to synchronously freeing\nonly the current object, and the older queued entries are leaked\nforever.\n\nTo trigger this, add the following to the kernel command line:\n\n  trace_event=sched_switch trace_trigger=sched_switch.traceon,sched_switch.traceon\n\nThe second traceon trigger will fail and be freed. This triggers a NULL\npointer dereference and crashes the kernel.\n\nKeep the deferred boot-time behavior, but when kthread creation fails,\ndrain the whole queued list synchronously. Do the same in the late-init\ndrain path so queued entries are not stranded there either.","Type":"Description","Title":"tracing: Drain deferred trigger frees if kthread creation fails"}]}}}