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GHSA-X3MJ-VJPH-62QR

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-15 06:32

Details

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix NMI/tracepoint re-entry deadlock on lru locks

NMI and tracepoint BPF programs can re-enter the per-CPU or global LRU lock that bpf_lru_pop_free()/push_free() already hold on the same CPU, AA-deadlocking. Lockdep reports "inconsistent {INITIAL USE} -> {IN-NMI}" on &l->lock (syzbot c69a0a2c816716f1e0d5) and "possible recursive locking detected" on &loc_l->lock (syzbot 18b26edb69b2e19f3b33).

Prior trylock and rqspinlock based fixes (see links) were nacked because compromised on reliability.

This patch converts every LRU lock site to rqspinlock_t and adds a recovery path for some failure windows to avoid node leaks.

Failure recovery:

*_pop_free top-level: return NULL; prealloc_lru_pop() already treats that as no-free-element (-ENOMEM).
Cross-CPU steal: skip the victim's locked loc_l, try next CPU.
Post-steal local lock fail: publish stolen node to lockless per-CPU free_llist; next pop on this CPU picks it up.
push_free fail: mark node pending_free=1. __local_list_flush(), __local_list_pop_pending() reclaim the node from pending_list. __bpf_lru_list_shrink_inactive() reclaims the node from inactive list. Nodes from active list are reclaimed by __bpf_lru_list_shrink() or after __bpf_lru_list_rotate_active() demotes it to the inactive.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74337"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:34Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NMI/tracepoint re-entry deadlock on lru locks\n\nNMI and tracepoint BPF programs can re-enter the per-CPU or global\nLRU lock that bpf_lru_pop_free()/push_free() already hold on the\nsame CPU, AA-deadlocking. Lockdep reports \"inconsistent\n{INITIAL USE} -\u003e {IN-NMI}\" on \u0026l-\u003elock (syzbot c69a0a2c816716f1e0d5)\nand \"possible recursive locking detected\" on \u0026loc_l-\u003elock (syzbot\n18b26edb69b2e19f3b33).\n\nPrior trylock and rqspinlock based fixes (see links) were nacked\nbecause compromised on reliability.\n\nThis patch converts every LRU lock site to rqspinlock_t and adds a\nrecovery path for some failure windows to avoid node leaks.\n\nFailure recovery:\n\n - *_pop_free top-level: return NULL; prealloc_lru_pop() already\n   treats that as no-free-element (-ENOMEM).\n\n - Cross-CPU steal: skip the victim\u0027s locked loc_l, try next CPU.\n\n - Post-steal local lock fail: publish stolen node to lockless\n   per-CPU free_llist; next pop on this CPU picks it up.\n\n - push_free fail: mark node pending_free=1. __local_list_flush(),\n   __local_list_pop_pending() reclaim the node from pending_list.\n   __bpf_lru_list_shrink_inactive() reclaims the node from inactive\n   list. Nodes from active list are reclaimed by __bpf_lru_list_shrink()\n   or after __bpf_lru_list_rotate_active() demotes it to the inactive.",
  "id": "GHSA-x3mj-vjph-62qr",
  "modified": "2026-08-15T06:32:30Z",
  "published": "2026-08-15T06:32:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74337"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/440a2fdbb40608d55a7b11f2be53592a3785131d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/89edbdfc5d0308cef57b71359331de5c4ddbf763"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8b0510cc3a4a000d4ed1a56cd96231f3d3ba94c5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-74337 (GCVE-0-2026-74337)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:58 – Updated: 2026-08-17 05:17

Title

bpf: Fix NMI/tracepoint re-entry deadlock on lru locks

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix NMI/tracepoint re-entry deadlock on lru locks NMI and tracepoint BPF programs can re-enter the per-CPU or global LRU lock that bpf_lru_pop_free()/push_free() already hold on the same CPU, AA-deadlocking. Lockdep reports "inconsistent {INITIAL USE} -> {IN-NMI}" on &l->lock (syzbot c69a0a2c816716f1e0d5) and "possible recursive locking detected" on &loc_l->lock (syzbot 18b26edb69b2e19f3b33). Prior trylock and rqspinlock based fixes (see links) were nacked because compromised on reliability. This patch converts every LRU lock site to rqspinlock_t and adds a recovery path for some failure windows to avoid node leaks. Failure recovery: - *_pop_free top-level: return NULL; prealloc_lru_pop() already treats that as no-free-element (-ENOMEM). - Cross-CPU steal: skip the victim's locked loc_l, try next CPU. - Post-steal local lock fail: publish stolen node to lockless per-CPU free_llist; next pop on this CPU picks it up. - push_free fail: mark node pending_free=1. __local_list_flush(), __local_list_pop_pending() reclaim the node from pending_list. __bpf_lru_list_shrink_inactive() reclaims the node from inactive list. Nodes from active list are reclaimed by __bpf_lru_list_shrink() or after __bpf_lru_list_rotate_active() demotes it to the inactive.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/8b0510cc3a4a000d4…
https://git.kernel.org/stable/c/440a2fdbb40608d55…
https://git.kernel.org/stable/c/89edbdfc5d0308cef…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3a08c2fd763450a927d1130de078d6f9e74944fb , < 8b0510cc3a4a000d4ed1a56cd96231f3d3ba94c5 (git) Affected: 3a08c2fd763450a927d1130de078d6f9e74944fb , < 440a2fdbb40608d55a7b11f2be53592a3785131d (git) Affected: 3a08c2fd763450a927d1130de078d6f9e74944fb , < 89edbdfc5d0308cef57b71359331de5c4ddbf763 (git)
Linux	Linux	Affected: 4.10 Unaffected: 0 , < 4.10 (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/bpf_lru_list.c",
            "kernel/bpf/bpf_lru_list.h"
          ],
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          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "3a08c2fd763450a927d1130de078d6f9e74944fb",
              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
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            {
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              "status": "affected",
              "version": "3a08c2fd763450a927d1130de078d6f9e74944fb",
              "versionType": "git"
            }
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        },
        {
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.10"
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              "version": "0",
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            },
            {
              "lessThanOrEqual": "6.18.*",
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              "versionType": "semver"
            },
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              "version": "7.1.5",
              "versionType": "semver"
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              "lessThanOrEqual": "*",
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              "cpeMatch": [
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                  "vulnerable": true
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              ],
              "negate": false,
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NMI/tracepoint re-entry deadlock on lru locks\n\nNMI and tracepoint BPF programs can re-enter the per-CPU or global\nLRU lock that bpf_lru_pop_free()/push_free() already hold on the\nsame CPU, AA-deadlocking. Lockdep reports \"inconsistent\n{INITIAL USE} -\u003e {IN-NMI}\" on \u0026l-\u003elock (syzbot c69a0a2c816716f1e0d5)\nand \"possible recursive locking detected\" on \u0026loc_l-\u003elock (syzbot\n18b26edb69b2e19f3b33).\n\nPrior trylock and rqspinlock based fixes (see links) were nacked\nbecause compromised on reliability.\n\nThis patch converts every LRU lock site to rqspinlock_t and adds a\nrecovery path for some failure windows to avoid node leaks.\n\nFailure recovery:\n\n - *_pop_free top-level: return NULL; prealloc_lru_pop() already\n   treats that as no-free-element (-ENOMEM).\n\n - Cross-CPU steal: skip the victim\u0027s locked loc_l, try next CPU.\n\n - Post-steal local lock fail: publish stolen node to lockless\n   per-CPU free_llist; next pop on this CPU picks it up.\n\n - push_free fail: mark node pending_free=1. __local_list_flush(),\n   __local_list_pop_pending() reclaim the node from pending_list.\n   __bpf_lru_list_shrink_inactive() reclaims the node from inactive\n   list. Nodes from active list are reclaimed by __bpf_lru_list_shrink()\n   or after __bpf_lru_list_rotate_active() demotes it to the inactive."
        }
      ],
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        "dateUpdated": "2026-08-17T05:17:29.070Z",
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        {
          "url": "https://git.kernel.org/stable/c/89edbdfc5d0308cef57b71359331de5c4ddbf763"
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    "datePublished": "2026-08-15T05:58:28.518Z",
    "dateReserved": "2026-08-15T05:44:03.885Z",
    "dateUpdated": "2026-08-17T05:17:29.070Z",
    "state": "PUBLISHED"
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  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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GHSA-X3MJ-VJPH-62QR

CVE-2026-74337 (GCVE-0-2026-74337)

Tags

Sightings

Nomenclature