CVE-2026-97936

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix memory corruption from the histogram stacktrace modifier parse_field() sets HIST_FIELD_FL_STACKTRACE from the ".stacktrace" modifier before it looks the field name up, and nothing afterwards checks that the name resolved to a field which holds a stacktrace. create_hist_field() picks HIST_FIELD_FN_STACK on the strength of the field pointer alone, which reads a __data_loc word from the record and follows its low 16 bits as an offset into the same record. event_hist_trigger() takes the first word there as an entry count and copies that many longs into a 31 entry array: n_entries = *stack; memcpy(entries, ++stack, n_entries * sizeof(unsigned long)); Neither end of that copy is bounded, and the count is whatever the event holds at the offset, so any field will do: # cd /sys/kernel/tracing/events/sched/sched_process_fork # echo 'hist:keys=parent_pid.stacktrace' > trigger # (true) BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:rb_insert_color+0x18/0x130 timerqueue_linked_add+0x7e/0xd0 enqueue_hrtimer+0x39/0xb0 __hrtimer_run_queues+0x10f/0x1f0 </IRQ> RIP: 0010:memcpy+0xc/0x30 event_hist_trigger+0x165/0x690 The timer interrupt landed on the rbtree the copy had already run over. No debug options are needed for this; KASAN reports the same write as an out-of-bounds read of 13835058055416381440 bytes. Documentation/trace/histogram.rst already states the rule, "must be a long[] type", so enforce it once the name has been resolved. Names which resolve to no field at all, "hitcount.stacktrace" and the common_* pseudo-fields, are refused for the same reason: they hold no stacktrace to read.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-09-25 11:17:20.963000

Last modified

2026-10-19 10:17:44.623000

View original CVE JSON

{
  "id": "CVE-2026-97936",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:20.963",
  "lastModified": "2026-10-19T10:17:44.623",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix memory corruption from the histogram stacktrace modifier\n\nparse_field() sets HIST_FIELD_FL_STACKTRACE from the \".stacktrace\"\nmodifier before it looks the field name up, and nothing afterwards\nchecks that the name resolved to a field which holds a stacktrace.\ncreate_hist_field() picks HIST_FIELD_FN_STACK on the strength of the\nfield pointer alone, which reads a __data_loc word from the record and\nfollows its low 16 bits as an offset into the same record.\nevent_hist_trigger() takes the first word there as an entry count and\ncopies that many longs into a 31 entry array:\n\n\tn_entries = *stack;\n\tmemcpy(entries, ++stack, n_entries * sizeof(unsigned long));\n\nNeither end of that copy is bounded, and the count is whatever the event\nholds at the offset, so any field will do:\n\n  # cd /sys/kernel/tracing/events/sched/sched_process_fork\n  # echo 'hist:keys=parent_pid.stacktrace' > trigger\n  # (true)\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000008\n  RIP: 0010:rb_insert_color+0x18/0x130\n   timerqueue_linked_add+0x7e/0xd0\n   enqueue_hrtimer+0x39/0xb0\n   __hrtimer_run_queues+0x10f/0x1f0\n   </IRQ>\n  RIP: 0010:memcpy+0xc/0x30\n   event_hist_trigger+0x165/0x690\n\nThe timer interrupt landed on the rbtree the copy had already run over.\nNo debug options are needed for this; KASAN reports the same write as an\nout-of-bounds read of 13835058055416381440 bytes.\n\nDocumentation/trace/histogram.rst already states the rule, \"must be a\nlong[] type\", so enforce it once the name has been resolved. Names which\nresolve to no field at all, \"hitcount.stacktrace\" and the common_*\npseudo-fields, are refused for the same reason: they hold no stacktrace\nto read."
    }
  ],
  "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": "cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314",
              "lessThan": "98da3379cdee343f671dac89b9afbd8b071f2591",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314",
              "lessThan": "e183b84968d4a6ea476d806ea97668405aa56880",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314",
              "lessThan": "57bfc2a17954d173d2a4182f3b582ffbb23aff64",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314",
              "lessThan": "55caaf25da2c2bb9b75307e4c868726cb954b1d6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc5fc8bfc961eeb99b7e8dffbeff7a3f6995d314",
              "lessThan": "a5e70ba87ca8ebc79b4e63de302d03b0625fe153",
              "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": "6.3",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.3",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.111",
              "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/55caaf25da2c2bb9b75307e4c868726cb954b1d6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/57bfc2a17954d173d2a4182f3b582ffbb23aff64",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/98da3379cdee343f671dac89b9afbd8b071f2591",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a5e70ba87ca8ebc79b4e63de302d03b0625fe153",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e183b84968d4a6ea476d806ea97668405aa56880",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}