CVE-2026-97935

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Set the trace clock before registering the histogram trigger hist_register_trigger() puts the trigger on the global named_triggers list in cmd_ops->init(), and only then sets the trace clock: if (data->cmd_ops->init) { ret = data->cmd_ops->init(data); if (ret < 0) goto out; } if (hist_data->enable_timestamps) { ret = tracing_set_clock(file->tr, hist_data->attrs->clock); if (ret) { hist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock)); goto out; } The clock string is not checked anywhere before that call, so a named trigger using common_timestamp with an unknown clock fails after it has already become findable. event_hist_trigger_parse() then frees it without taking it off the list, and the next lookup by name reads the freed object: ~# cd /sys/kernel/tracing/events/sched/sched_switch ~# echo 'hist:name=foo:keys=common_pid:ts=common_timestamp:clock=bogus' > trigger bash: echo: write error: Invalid argument ~# echo 'hist:name=foo:keys=common_pid' > trigger BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0 Read of size 8 at addr ffff88800915d760 by task init/1 find_named_trigger+0xac/0xc0 hist_register_trigger+0xc1/0x900 event_hist_trigger_parse+0x3146/0x6af0 event_trigger_write+0xce/0x160 Freed by task 63: kfree+0x154/0x420 trigger_kthread_fn+0xfd/0x160 Set the clock before the trigger is registered, so that nothing which can fail runs after it is published, the way commit 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers list") moved the registration below the rest of the setup. tracing_set_filter_buffering() is reference counted, so the init failure path has to drop the reference that the clock block now takes first.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-25 11:17:20.850000

Last modified

2026-10-30 13:21:10.743000

View original CVE JSON

{
  "id": "CVE-2026-97935",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:20.850",
  "lastModified": "2026-10-30T13:21:10.743",
  "vulnStatus": "Received",
  "cveTags": [],
  "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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "kernel/trace/trace_events_hist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "a4072fe85ba3671720cab0788291af953db27318",
              "lessThan": "85e6df6e9cd489de8e238596a68b89eee0c03b88",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a4072fe85ba3671720cab0788291af953db27318",
              "lessThan": "3568dabef3fb56517777ab981584f72ab1e90186",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a4072fe85ba3671720cab0788291af953db27318",
              "lessThan": "c7b77c22adcf314ec8aa4807f01914dcbc62ed54",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a4072fe85ba3671720cab0788291af953db27318",
              "lessThan": "578d39ab420b18b76a12fc8d0573ec041a84da28",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a4072fe85ba3671720cab0788291af953db27318",
              "lessThan": "cc6c4cf565b0c187c61ffd2e67a4dfb2427675ad",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a4072fe85ba3671720cab0788291af953db27318",
              "lessThan": "cfad128171f8e2237a3c723d6478ef2cfb3b9127",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a4072fe85ba3671720cab0788291af953db27318",
              "lessThan": "65d1e28198f344832a8a63e8ccf84b8f65b92a32",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a4072fe85ba3671720cab0788291af953db27318",
              "lessThan": "6ede78d0563a2a3ae3e46f9c07cedb5d79645429",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "kernel/trace/trace_events_hist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.17",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.17",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.273",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.224",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.53",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.7",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3568dabef3fb56517777ab981584f72ab1e90186",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/578d39ab420b18b76a12fc8d0573ec041a84da28",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/65d1e28198f344832a8a63e8ccf84b8f65b92a32",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6ede78d0563a2a3ae3e46f9c07cedb5d79645429",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/85e6df6e9cd489de8e238596a68b89eee0c03b88",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c7b77c22adcf314ec8aa4807f01914dcbc62ed54",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cc6c4cf565b0c187c61ffd2e67a4dfb2427675ad",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cfad128171f8e2237a3c723d6478ef2cfb3b9127",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}