{"api_version":"1","generated_at":"2026-09-27T22:51:22+00:00","cve":"CVE-2026-97935","urls":{"html":"https://cve.report/CVE-2026-97935","api":"https://cve.report/api/cve/CVE-2026-97935.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-97935","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-97935"},"summary":{"title":"tracing: Set the trace clock before registering the histogram trigger","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Set the trace clock before registering the histogram trigger\n\nhist_register_trigger() puts the trigger on the global named_triggers\nlist in cmd_ops->init(), and only then sets the trace clock:\n\n\tif (data->cmd_ops->init) {\n\t\tret = data->cmd_ops->init(data);\n\t\tif (ret < 0)\n\t\t\tgoto out;\n\t}\n\n\tif (hist_data->enable_timestamps) {\n\t\tret = tracing_set_clock(file->tr, hist_data->attrs->clock);\n\t\tif (ret) {\n\t\t\thist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));\n\t\t\tgoto out;\n\t\t}\n\nThe clock string is not checked anywhere before that call, so a named\ntrigger using common_timestamp with an unknown clock fails after it has\nalready become findable. event_hist_trigger_parse() then frees it\nwithout taking it off the list, and the next lookup by name reads the\nfreed object:\n\n ~# cd /sys/kernel/tracing/events/sched/sched_switch\n ~# echo 'hist:name=foo:keys=common_pid:ts=common_timestamp:clock=bogus' > trigger\n bash: echo: write error: Invalid argument\n ~# echo 'hist:name=foo:keys=common_pid' > trigger\n\n  BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0\n  Read of size 8 at addr ffff88800915d760 by task init/1\n   find_named_trigger+0xac/0xc0\n   hist_register_trigger+0xc1/0x900\n   event_hist_trigger_parse+0x3146/0x6af0\n   event_trigger_write+0xce/0x160\n  Freed by task 63:\n   kfree+0x154/0x420\n   trigger_kthread_fn+0xfd/0x160\n\nSet the clock before the trigger is registered, so that nothing which\ncan fail runs after it is published, the way commit 6f86bdeab633\n(\"tracing: Fix bad hist from corrupting named_triggers list\") moved the\nregistration below the rest of the setup.\n\ntracing_set_filter_buffering() is reference counted, so the init failure\npath has to drop the reference that the clock block now takes first.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:20","updated_at":"2026-09-25 11:17:20"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/65d1e28198f344832a8a63e8ccf84b8f65b92a32","name":"https://git.kernel.org/stable/c/65d1e28198f344832a8a63e8ccf84b8f65b92a32","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/cfad128171f8e2237a3c723d6478ef2cfb3b9127","name":"https://git.kernel.org/stable/c/cfad128171f8e2237a3c723d6478ef2cfb3b9127","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6ede78d0563a2a3ae3e46f9c07cedb5d79645429","name":"https://git.kernel.org/stable/c/6ede78d0563a2a3ae3e46f9c07cedb5d79645429","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97935","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97935","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a4072fe85ba3671720cab0788291af953db27318 cfad128171f8e2237a3c723d6478ef2cfb3b9127 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a4072fe85ba3671720cab0788291af953db27318 65d1e28198f344832a8a63e8ccf84b8f65b92a32 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a4072fe85ba3671720cab0788291af953db27318 6ede78d0563a2a3ae3e46f9c07cedb5d79645429 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.17","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.17 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":"97935","cve":"CVE-2026-97935","epss":"0.001660000","percentile":"0.052010000","score_date":"2026-09-26","updated_at":"2026-09-27 00:04:20"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["kernel/trace/trace_events_hist.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"cfad128171f8e2237a3c723d6478ef2cfb3b9127","status":"affected","version":"a4072fe85ba3671720cab0788291af953db27318","versionType":"git"},{"lessThan":"65d1e28198f344832a8a63e8ccf84b8f65b92a32","status":"affected","version":"a4072fe85ba3671720cab0788291af953db27318","versionType":"git"},{"lessThan":"6ede78d0563a2a3ae3e46f9c07cedb5d79645429","status":"affected","version":"a4072fe85ba3671720cab0788291af953db27318","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["kernel/trace/trace_events_hist.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.17"},{"lessThan":"4.17","status":"unaffected","version":"0","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":"6.18.53","versionStartIncluding":"4.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"4.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc3","versionStartIncluding":"4.17","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Set the trace clock before registering the histogram trigger\n\nhist_register_trigger() puts the trigger on the global named_triggers\nlist in cmd_ops->init(), and only then sets the trace clock:\n\n\tif (data->cmd_ops->init) {\n\t\tret = data->cmd_ops->init(data);\n\t\tif (ret < 0)\n\t\t\tgoto out;\n\t}\n\n\tif (hist_data->enable_timestamps) {\n\t\tret = tracing_set_clock(file->tr, hist_data->attrs->clock);\n\t\tif (ret) {\n\t\t\thist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));\n\t\t\tgoto out;\n\t\t}\n\nThe clock string is not checked anywhere before that call, so a named\ntrigger using common_timestamp with an unknown clock fails after it has\nalready become findable. event_hist_trigger_parse() then frees it\nwithout taking it off the list, and the next lookup by name reads the\nfreed object:\n\n ~# cd /sys/kernel/tracing/events/sched/sched_switch\n ~# echo 'hist:name=foo:keys=common_pid:ts=common_timestamp:clock=bogus' > trigger\n bash: echo: write error: Invalid argument\n ~# echo 'hist:name=foo:keys=common_pid' > trigger\n\n  BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0\n  Read of size 8 at addr ffff88800915d760 by task init/1\n   find_named_trigger+0xac/0xc0\n   hist_register_trigger+0xc1/0x900\n   event_hist_trigger_parse+0x3146/0x6af0\n   event_trigger_write+0xce/0x160\n  Freed by task 63:\n   kfree+0x154/0x420\n   trigger_kthread_fn+0xfd/0x160\n\nSet the clock before the trigger is registered, so that nothing which\ncan fail runs after it is published, the way commit 6f86bdeab633\n(\"tracing: Fix bad hist from corrupting named_triggers list\") moved the\nregistration below the rest of the setup.\n\ntracing_set_filter_buffering() is reference counted, so the init failure\npath has to drop the reference that the clock block now takes first."}],"providerMetadata":{"dateUpdated":"2026-09-25T10:22:49.820Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/cfad128171f8e2237a3c723d6478ef2cfb3b9127"},{"url":"https://git.kernel.org/stable/c/65d1e28198f344832a8a63e8ccf84b8f65b92a32"},{"url":"https://git.kernel.org/stable/c/6ede78d0563a2a3ae3e46f9c07cedb5d79645429"}],"title":"tracing: Set the trace clock before registering the histogram trigger","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-97935","datePublished":"2026-09-25T10:22:49.820Z","dateReserved":"2026-09-25T10:18:58.203Z","dateUpdated":"2026-09-25T10:22:49.820Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:20","lastModifiedDate":"2026-09-25 11:17:20","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"97935","Ordinal":"1","Title":"tracing: Set the trace clock before registering the histogram tr","CVE":"CVE-2026-97935","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"97935","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Set the trace clock before registering the histogram trigger\n\nhist_register_trigger() puts the trigger on the global named_triggers\nlist in cmd_ops->init(), and only then sets the trace clock:\n\n\tif (data->cmd_ops->init) {\n\t\tret = data->cmd_ops->init(data);\n\t\tif (ret < 0)\n\t\t\tgoto out;\n\t}\n\n\tif (hist_data->enable_timestamps) {\n\t\tret = tracing_set_clock(file->tr, hist_data->attrs->clock);\n\t\tif (ret) {\n\t\t\thist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock));\n\t\t\tgoto out;\n\t\t}\n\nThe clock string is not checked anywhere before that call, so a named\ntrigger using common_timestamp with an unknown clock fails after it has\nalready become findable. event_hist_trigger_parse() then frees it\nwithout taking it off the list, and the next lookup by name reads the\nfreed object:\n\n ~# cd /sys/kernel/tracing/events/sched/sched_switch\n ~# echo 'hist:name=foo:keys=common_pid:ts=common_timestamp:clock=bogus' > trigger\n bash: echo: write error: Invalid argument\n ~# echo 'hist:name=foo:keys=common_pid' > trigger\n\n  BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0\n  Read of size 8 at addr ffff88800915d760 by task init/1\n   find_named_trigger+0xac/0xc0\n   hist_register_trigger+0xc1/0x900\n   event_hist_trigger_parse+0x3146/0x6af0\n   event_trigger_write+0xce/0x160\n  Freed by task 63:\n   kfree+0x154/0x420\n   trigger_kthread_fn+0xfd/0x160\n\nSet the clock before the trigger is registered, so that nothing which\ncan fail runs after it is published, the way commit 6f86bdeab633\n(\"tracing: Fix bad hist from corrupting named_triggers list\") moved the\nregistration below the rest of the setup.\n\ntracing_set_filter_buffering() is reference counted, so the init failure\npath has to drop the reference that the clock block now takes first.","Type":"Description","Title":"tracing: Set the trace clock before registering the histogram tr"}]}}}