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CVE-2026-98378

Status: ReceivedUnscored—

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

bpf: Skip unsettled links in link iterator

bpf_link_prime() inserts a link into link_idr before anon_inode_getfile() succeeds and before bpf_link_settle() publishes the ID in link->id. bpf_link_by_id() treats such an ID-zero link as unsettled, but the link iterator takes a reference without this check.

If anon_inode_getfile() then fails, the creator removes the ID and frees its still-private link directly. The iterator is left with a dangling reference and its next bpf_link_put() accesses freed memory.

Treat ID-zero entries as transient in bpf_link_get_curr_or_next(), just as bpf_link_by_id() does.

Technical details traces, logs and code from the original report
  BUG: KASAN: slab-use-after-free in bpf_link_put
  Write of size 8 by task exp/384
  Call Trace:
  bpf_link_put                    kernel/bpf/syscall.c:3372
  bpf_link_seq_next               kernel/bpf/link_iter.c:33
  bpf_seq_read                    kernel/bpf/bpf_iter.c:158
  vfs_read                        fs/read_write.c:572
  ksys_read                       fs/read_write.c:716
  do_syscall_64                   arch/x86/entry/syscall_64.c:84
  entry_SYSCALL_64_after_hwframe  arch/x86/entry/entry_64.S:121
  Kernel panic - not syncing: KASAN: panic_on_warn set ...

CVSS

NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

References

Raw JSON (NVD)

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{
  "id": "CVE-2026-98378",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "9f88361273082825d9f0d13a543d49f9fa0d44a8",
              "lessThan": "68930f8d40ab4c10ca3b019f076136758fd100a8",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9f88361273082825d9f0d13a543d49f9fa0d44a8",
              "lessThan": "c251ed48bd9063cf7de6049421e78b6de989060f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9f88361273082825d9f0d13a543d49f9fa0d44a8",
              "lessThan": "798a61edbc436cacdb659927d067368eeb1e30e2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9f88361273082825d9f0d13a543d49f9fa0d44a8",
              "lessThan": "6e271f093d15d323f42de26f66556af53fa8e19f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9f88361273082825d9f0d13a543d49f9fa0d44a8",
              "lessThan": "87ce4b53b7436b50fc984f0a6afaf77f68ac5573",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9f88361273082825d9f0d13a543d49f9fa0d44a8",
              "lessThan": "50e80e2bb5e2be8515205b9c496b9640ddefa434",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "kernel/bpf/syscall.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.19",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.1.189",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.112",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.55",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.9",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc5",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "kernel/bpf/syscall.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-10-09T08:16:56.123",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/50e80e2bb5e2be8515205b9c496b9640ddefa434",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/68930f8d40ab4c10ca3b019f076136758fd100a8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6e271f093d15d323f42de26f66556af53fa8e19f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/798a61edbc436cacdb659927d067368eeb1e30e2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/87ce4b53b7436b50fc984f0a6afaf77f68ac5573",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c251ed48bd9063cf7de6049421e78b6de989060f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Skip unsettled links in link iterator\n\nbpf_link_prime() inserts a link into link_idr before anon_inode_getfile()\nsucceeds and before bpf_link_settle() publishes the ID in link->id.\nbpf_link_by_id() treats such an ID-zero link as unsettled, but the link\niterator takes a reference without this check.\n\nIf anon_inode_getfile() then fails, the creator removes the ID and frees\nits still-private link directly.  The iterator is left with a dangling\nreference and its next bpf_link_put() accesses freed memory.\n\nTreat ID-zero entries as transient in bpf_link_get_curr_or_next(), just as\nbpf_link_by_id() does.\n\n  BUG: KASAN: slab-use-after-free in bpf_link_put\n  Write of size 8 by task exp/384\n  Call Trace:\n  bpf_link_put                    kernel/bpf/syscall.c:3372\n  bpf_link_seq_next               kernel/bpf/link_iter.c:33\n  bpf_seq_read                    kernel/bpf/bpf_iter.c:158\n  vfs_read                        fs/read_write.c:572\n  ksys_read                       fs/read_write.c:716\n  do_syscall_64                   arch/x86/entry/syscall_64.c:84\n  entry_SYSCALL_64_after_hwframe  arch/x86/entry/entry_64.S:121\n  Kernel panic - not syncing: KASAN: panic_on_warn set ..."
    }
  ],
  "lastModified": "2026-10-09T08:16:56.123",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}