CVE-2026-74400 (GCVE-0-2026-74400)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:59 – Updated: 2026-08-17 05:18
VLAI
Title
bpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries bpf_set_dentry_xattr and bpf_remove_dentry_xattr BPF kfuncs attempt to lock the inode of the supplied dentry without checking if it is NULL. If a negative dentry is passed (e.g. from security_inode_create), d_inode(dentry) returns NULL, and inode_lock(inode) will cause a NULL pointer dereference. Trivially fix this by adding a NULL check for inode before attempting to lock it, returning -EINVAL if it is NULL. Additionally, drop WARN_ON(!inode) in bpf_xattr_read_permission() and bpf_xattr_write_permission(). These warnings could be triggered by passing a negative dentry to bpf_get_dentry_xattr() or the _locked variants of the xattr kfuncs, potentially causing a Denial of Service on systems with panic_on_warn enabled. Instead, simply return -EINVAL.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 56467292794b800164df20c076c409ac548e56ec , < e003f3a4be738f650e283e92d07017c3fef8da52 (git)
Affected: 56467292794b800164df20c076c409ac548e56ec , < 0160edf2af51c5fde742973742c5d10497901b21 (git)
Affected: 56467292794b800164df20c076c409ac548e56ec , < 07410646f6ff1d23222f105ccab778957d401bbe (git)
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Linux Linux Affected: 6.15
Unaffected: 0 , < 6.15 (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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{
  "containers": {
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      "affected": [
        {
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          "product": "Linux",
          "programFiles": [
            "fs/bpf_fs_kfuncs.c"
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              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries\n\nbpf_set_dentry_xattr and bpf_remove_dentry_xattr BPF kfuncs attempt to\nlock the inode of the supplied dentry without checking if it is\nNULL. If a negative dentry is passed (e.g. from\nsecurity_inode_create), d_inode(dentry) returns NULL, and\ninode_lock(inode) will cause a NULL pointer dereference.\n\nTrivially fix this by adding a NULL check for inode before attempting\nto lock it, returning -EINVAL if it is NULL.\n\nAdditionally, drop WARN_ON(!inode) in bpf_xattr_read_permission() and\nbpf_xattr_write_permission(). These warnings could be triggered by\npassing a negative dentry to bpf_get_dentry_xattr() or the _locked\nvariants of the xattr kfuncs, potentially causing a Denial of Service\non systems with panic_on_warn enabled. Instead, simply return -EINVAL."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:18:40.094Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/e003f3a4be738f650e283e92d07017c3fef8da52"
        },
        {
          "url": "https://git.kernel.org/stable/c/0160edf2af51c5fde742973742c5d10497901b21"
        },
        {
          "url": "https://git.kernel.org/stable/c/07410646f6ff1d23222f105ccab778957d401bbe"
        }
      ],
      "title": "bpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74400",
    "datePublished": "2026-08-15T05:59:11.450Z",
    "dateReserved": "2026-08-15T05:44:03.892Z",
    "dateUpdated": "2026-08-17T05:18:40.094Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
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      "date": "2026-09-21",
      "epss": "0.00166",
      "percentile": "0.0628"
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                "programFiles": [
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        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries\n\nbpf_set_dentry_xattr and bpf_remove_dentry_xattr BPF kfuncs attempt to\nlock the inode of the supplied dentry without checking if it is\nNULL. If a negative dentry is passed (e.g. from\nsecurity_inode_create), d_inode(dentry) returns NULL, and\ninode_lock(inode) will cause a NULL pointer dereference.\n\nTrivially fix this by adding a NULL check for inode before attempting\nto lock it, returning -EINVAL if it is NULL.\n\nAdditionally, drop WARN_ON(!inode) in bpf_xattr_read_permission() and\nbpf_xattr_write_permission(). These warnings could be triggered by\npassing a negative dentry to bpf_get_dentry_xattr() or the _locked\nvariants of the xattr kfuncs, potentially causing a Denial of Service\non systems with panic_on_warn enabled. Instead, simply return -EINVAL."
          }
        ],
        "id": "CVE-2026-74400",
        "lastModified": "2026-08-17T06:19:35.183",
        "metrics": {},
        "published": "2026-08-15T06:22:42.030",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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          }
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        "vulnStatus": "Received"
      }
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      "current_release_date": "2026-08-20T22:19:19+00:00",
      "cve": "CVE-2026-74400",
      "id": "CVE-2026-74400",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "76",
      "product_status:known_not_affected": "198",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: bpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74400.json",
      "version": "3"
    },
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      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-15T01:21:34Z",
      "cve": "CVE-2026-74400",
      "id": "CVE-2026-74400",
      "initial_release_date": "2026-08-27T16:51:29Z",
      "product_status:known_affected": "12",
      "product_status:known_not_affected": "350",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-74400",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-74400.json",
      "version": "4"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.


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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.