{"id":"CVE-2026-97935","title":"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(), an…","summary":"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(), an…","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-825","CWE-416"],"vendor":"Linux","product":"Linux","affected":["Linux >= a4072fe85ba3671720cab0788291af953db27318 < cc6c4cf565b0c187c61ffd2e67a4dfb2427675ad","Linux >= a4072fe85ba3671720cab0788291af953db27318 < cfad128171f8e2237a3c723d6478ef2cfb3b9127","Linux >= a4072fe85ba3671720cab0788291af953db27318 < 65d1e28198f344832a8a63e8ccf84b8f65b92a32","Linux >= a4072fe85ba3671720cab0788291af953db27318 < 6ede78d0563a2a3ae3e46f9c07cedb5d79645429","Linux 4.17"],"published":"2026-09-25","updated":"2026-10-03","sourceUpdated":"2026-10-03T11:18:19.153","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97935","references":[{"url":"https://git.kernel.org/stable/c/65d1e28198f344832a8a63e8ccf84b8f65b92a32","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6ede78d0563a2a3ae3e46f9c07cedb5d79645429","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cc6c4cf565b0c187c61ffd2e67a4dfb2427675ad","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cfad128171f8e2237a3c723d6478ef2cfb3b9127","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97935.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-97935"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541269"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97935"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97935"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97935.mbox"},{"url":"https://git.kernel.org/stable/c/578d39ab420b18b76a12fc8d0573ec041a84da28"},{"url":"https://kernelcve.org/list/?q=CVE-2026-97935"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00168,"epssPercentile":0.06155,"cvssSource":"vendor","ingestedAt":"2026-09-25T11:06:38.885Z","slug":"CVE-2026-97935","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97935.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":213425,"id":"CVE-2026-97935","ts":1790754716094,"field":"cvss","old":null,"new":"7"},{"seq":213424,"id":"CVE-2026-97935","ts":1790754716094,"field":"severity","old":"none","new":"high"}]}