CVE-2026-74605 (GCVE-0-2026-74605)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:31 – Updated: 2026-08-25 05:40
VLAI
Title
eventfs: Use children field for rcu head and add memory barriers
Summary
In the Linux kernel, the following vulnerability has been resolved: eventfs: Use children field for rcu head and add memory barriers When an eventfs inode is freed, it sets ei->is_freed and then uses its ei->list to add it to the srcu link list as the list field is a union with the rcu list head. As the ei->list is used to iterate over an SRCU protected list without taking the eventfs_mutex, there's nothing stopping the iteration over that list to see the ei->rcu instead of the ei->list and it will read a corrupt target. To fix this, change the union of the rcu list head with the children list. On freeing the eventfs inode, set the is_free and execute a smp_wmb() before adding the eventfs inode to the SRCU list. On iteration of the ei->children list, at the start, execute a smp_rmb() and then read the is_freed of the ei to see if the children list is still valid. If is_freed is set, then the ei_child read is not valid and the loop should exit immediately.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 704f960dbee2f1634f4b4e16f208cb16eaf41c1e , < 004f7232e49730448f91665e76bdd7dff8e0c638 (git)
Affected: 704f960dbee2f1634f4b4e16f208cb16eaf41c1e , < f0ece16ffca7384787b692431961ce202907acf5 (git)
Affected: f3f41f444b321ec393edbc251e024fd62658ce55 (git)
Affected: 305c4e4d80aca2c2d9cf2ebdea56e2eca6d3a6aa (git)
Affected: 6.6.18 , < 6.7 (semver)
Affected: 6.7.6 , < 6.8 (semver)
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Linux Linux Affected: 6.8
Unaffected: 0 , < 6.8 (semver)
Unaffected: 7.1.9 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/tracefs/event_inode.c",
            "fs/tracefs/internal.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "versionType": "git"
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              "status": "affected",
              "version": "704f960dbee2f1634f4b4e16f208cb16eaf41c1e",
              "versionType": "git"
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          "product": "Linux",
          "programFiles": [
            "fs/tracefs/event_inode.c",
            "fs/tracefs/internal.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "6.8"
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "*",
              "status": "unaffected",
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              "versionType": "original_commit_for_fix"
            }
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        }
      ],
      "cpeApplicability": [
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                  "versionStartIncluding": "6.8",
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                  "versionStartIncluding": "6.8",
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              ],
              "negate": false,
              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\neventfs: Use children field for rcu head and add memory barriers\n\nWhen an eventfs inode is freed, it sets ei-\u003eis_freed and then uses its\nei-\u003elist to add it to the srcu link list as the list field is a union with\nthe rcu list head. As the ei-\u003elist is used to iterate over an SRCU\nprotected list without taking the eventfs_mutex, there\u0027s nothing stopping\nthe iteration over that list to see the ei-\u003ercu instead of the ei-\u003elist\nand it will read a corrupt target.\n\nTo fix this, change the union of the rcu list head with the children list.\nOn freeing the eventfs inode, set the is_free and execute a smp_wmb()\nbefore adding the eventfs inode to the SRCU list.\n\nOn iteration of the ei-\u003echildren list, at the start, execute a smp_rmb()\nand then read the is_freed of the ei to see if the children list is still\nvalid. If is_freed is set, then the ei_child read is not valid and the\nloop should exit immediately."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is reached only via local syscalls (getdents64/readdir on tracefs eventfs directories through eventfs_iterate); tracefs is a kernel pseudo-filesystem under /sys/kernel/tracing with no network, adjacent-wireless, or physical-device entry path.\nAC:L - A single multithreaded attacker can loop getdents on events/ or events/kprobes/ while concurrently adding/removing kprobes via kprobe_events writes that call eventfs_remove_dir; the attacker controls both the SRCU list walk and the free path, making the race reliably triggerable.\nPR:L - Exploitation needs only local tracefs read/write access (getdents plus kprobe_events to create/remove eventfs children); kprobe_events checks only LOCKDOWN_TRACEFS and DAC with no capable(), and tracing-group gid mounts, Android/ChromeOS, and developer systems commonly grant this to unprivileged users.\nUI:N - The attacker performs all concurrent directory reads and dynamic event removals in their own process; no separate victim mount, click, or configuration action is required beyond tracefs already being accessible on the system.\nS:U - The union misuse causes kernel heap/list corruption and use-after-free within the tracing filesystem subsystem on the same host; it does not cross VM, container, IOMMU, or other security boundaries to affect a different authority.\nC:H - During list_for_each_entry_srcu over ei-\u003echildren, a concurrently freed child repurposes ei-\u003elist (union with rcu_head) for SRCU teardown, so the iterator follows corrupt list pointers and dereferences freed or attacker-influenced kernel memory typical of UAF read primitives.\nI:H - Corrupt SRCU list traversal over freed eventfs_inode objects is classic kernel UAF memory corruption that can be combined with heap grooming from repeated kprobe create/delete to obtain arbitrary kernel writes and local privilege escalation, not merely a bounded crash.\nA:H - Following a child\u0027s list.next after the list/rcu union is switched during free_ei() readily causes invalid pointer dereferences, kernel oops, or panic; the race can be retriggered at will by alternating getdents with dynamic event teardown."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T05:40:29.836Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/004f7232e49730448f91665e76bdd7dff8e0c638"
        },
        {
          "url": "https://git.kernel.org/stable/c/f0ece16ffca7384787b692431961ce202907acf5"
        }
      ],
      "title": "eventfs: Use children field for rcu head and add memory barriers",
      "x_generator": {
        "engine": "bippy-1.2.0"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74605",
    "datePublished": "2026-08-22T15:31:53.063Z",
    "dateReserved": "2026-08-15T05:44:03.919Z",
    "dateUpdated": "2026-08-25T05:40:29.836Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-74605",
      "date": "2026-09-01",
      "epss": "0.0012",
      "percentile": "0.02079"
    },
    "microsoft_vex": {
      "current_release_date": "2026-08-24T14:46:30.000Z",
      "cve": "CVE-2026-74605",
      "id": "msrc_CVE-2026-74605",
      "initial_release_date": "2026-08-24T01:03:04.000Z",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "eventfs: Use children field for rcu head and add memory barriers",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74605.json",
      "version": "2"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-74605\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-22T16:16:32.977\",\"lastModified\":\"2026-08-25T06:18:36.947\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\neventfs: Use children field for rcu head and add memory barriers\\n\\nWhen an eventfs inode is freed, it sets ei-\u003eis_freed and then uses its\\nei-\u003elist to add it to the srcu link list as the list field is a union with\\nthe rcu list head. As the ei-\u003elist is used to iterate over an SRCU\\nprotected list without taking the eventfs_mutex, there\u0027s nothing stopping\\nthe iteration over that list to see the ei-\u003ercu instead of the ei-\u003elist\\nand it will read a corrupt target.\\n\\nTo fix this, change the union of the rcu list head with the children list.\\nOn freeing the eventfs inode, set the is_free and execute a smp_wmb()\\nbefore adding the eventfs inode to the SRCU list.\\n\\nOn iteration of the ei-\u003echildren list, at the start, execute a smp_rmb()\\nand then read the is_freed of the ei to see if the children list is still\\nvalid. If is_freed is set, then the ei_child read is not valid and the\\nloop should exit immediately.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/tracefs/event_inode.c\",\"fs/tracefs/internal.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"704f960dbee2f1634f4b4e16f208cb16eaf41c1e\",\"lessThan\":\"004f7232e49730448f91665e76bdd7dff8e0c638\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"704f960dbee2f1634f4b4e16f208cb16eaf41c1e\",\"lessThan\":\"f0ece16ffca7384787b692431961ce202907acf5\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f3f41f444b321ec393edbc251e024fd62658ce55\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"305c4e4d80aca2c2d9cf2ebdea56e2eca6d3a6aa\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"6.6.18\",\"lessThan\":\"6.7\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"6.7.6\",\"lessThan\":\"6.8\",\"versionType\":\"semver\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/tracefs/event_inode.c\",\"fs/tracefs/internal.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.8\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.8\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.9\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/004f7232e49730448f91665e76bdd7dff8e0c638\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f0ece16ffca7384787b692431961ce202907acf5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-25T08:50:30+00:00",
      "cve": "CVE-2026-74605",
      "id": "CVE-2026-74605",
      "initial_release_date": "2026-08-22T00:00:00+00:00",
      "product_status:known_affected": "76",
      "product_status:known_not_affected": "198",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: eventfs: Use children field for rcu head and add memory barriers",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74605.json",
      "version": "3"
    }
  }
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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