CVE-2026-98047

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Check ancestor frames for rbtree callbacks bpf_rbtree_add() invokes its comparator while the caller holds the root lock. The native insertion code retains raw parent and link pointers across the callback, so the verifier prohibits unlocking, consuming tree nodes, or changing RCU state from that callback. in_rbtree_lock_required_cb() only checks the innermost verifier frame. Static subprogram calls are permitted while holding a spin lock, and such a call pushes a frame without in_callback_fn set. Consequently, all callback restrictions disappear in the nested frame. The subprogram can unlock the tree, remove and drop the node being compared, then relock. Native insertion resumes with the stale parent pointer and links freed memory into the tree. Walk all active frames for the rbtree callback instead. Benign static subprograms remain permitted, while callback restrictions follow execution into nested frames.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-09-25 11:17:33.553000

Last modified

2026-10-21 13:21:20.180000

View original CVE JSON

{
  "id": "CVE-2026-98047",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:33.553",
  "lastModified": "2026-10-21T13:21:20.180",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check ancestor frames for rbtree callbacks\n\nbpf_rbtree_add() invokes its comparator while the caller holds the root\nlock. The native insertion code retains raw parent and link pointers across\nthe callback, so the verifier prohibits unlocking, consuming tree nodes,\nor changing RCU state from that callback.\n\nin_rbtree_lock_required_cb() only checks the innermost verifier frame.\nStatic subprogram calls are permitted while holding a spin lock, and such a\ncall pushes a frame without in_callback_fn set. Consequently, all callback\nrestrictions disappear in the nested frame. The subprogram can unlock the\ntree, remove and drop the node being compared, then relock. Native insertion\nresumes with the stale parent pointer and links freed memory into the tree.\n\nWalk all active frames for the rbtree callback instead. Benign static\nsubprograms remain permitted, while callback restrictions follow execution\ninto nested frames."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "a44b1334aadd82203f661adb9adb41e53ad0e8d1",
              "lessThan": "252e9b476af723edd299a5c71c389ec018e46656",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a44b1334aadd82203f661adb9adb41e53ad0e8d1",
              "lessThan": "b545fa447e09e6844868deb2bee228827fe54d15",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a44b1334aadd82203f661adb9adb41e53ad0e8d1",
              "lessThan": "2410cb2ac0416dd2795a81984c8c73d7250bd8c4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a44b1334aadd82203f661adb9adb41e53ad0e8d1",
              "lessThan": "369f4ce734570bdfedaa4b5ca50e2a3f6a892728",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.9",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.9",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.114",
              "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/2410cb2ac0416dd2795a81984c8c73d7250bd8c4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/252e9b476af723edd299a5c71c389ec018e46656",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/369f4ce734570bdfedaa4b5ca50e2a3f6a892728",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b545fa447e09e6844868deb2bee228827fe54d15",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}