CVE-2026-98037

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject untrusted allocated-object pointers When the final RCU read-side critical section ends, a local kptr is demoted to PTR_UNTRUSTED but retains MEM_ALLOC. The pointer may be NULL or may refer to an object whose lifetime is no longer protected. type_is_ptr_alloc_obj() nevertheless recognizes any PTR_TO_BTF_ID with MEM_ALLOC as a live allocated object. In particular, a refcount-only local kptr never carries NON_OWN_REF, so it still passes the bpf_refcount_acquire() argument check after RCU protection ends. The kfunc can then dereference NULL or stale memory. Make type_is_ptr_alloc_obj() reject PTR_UNTRUSTED pointers. Since type_is_non_owning_ref() is based on the same predicate, graph kfunc arguments obey the same live-object requirement. Fault-protected reads of the demoted pointer remain valid: writes are already rejected, and read fixups use bpf_may_fault_on_deref() rather than this predicate. [ kkd: Rewrote commit log ]

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-09-25 11:17:32.443000

Last modified

2026-10-19 10:17:57.647000

View original CVE JSON

{
  "id": "CVE-2026-98037",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:32.443",
  "lastModified": "2026-10-19T10:17:57.647",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject untrusted allocated-object pointers\n\nWhen the final RCU read-side critical section ends, a local kptr is demoted\nto PTR_UNTRUSTED but retains MEM_ALLOC. The pointer may be NULL or may refer\nto an object whose lifetime is no longer protected.\n\ntype_is_ptr_alloc_obj() nevertheless recognizes any PTR_TO_BTF_ID with\nMEM_ALLOC as a live allocated object. In particular, a refcount-only local\nkptr never carries NON_OWN_REF, so it still passes the\nbpf_refcount_acquire() argument check after RCU protection ends. The kfunc\ncan then dereference NULL or stale memory.\n\nMake type_is_ptr_alloc_obj() reject PTR_UNTRUSTED pointers. Since\ntype_is_non_owning_ref() is based on the same predicate, graph kfunc\narguments obey the same live-object requirement. Fault-protected reads of\nthe demoted pointer remain valid: writes are already rejected, and read\nfixups use bpf_may_fault_on_deref() rather than this predicate.\n\n[ kkd: Rewrote commit log ]"
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "include/linux/bpf_verifier.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "1b12171533a9bb23cf6fba7262b479028b65e1e8",
              "lessThan": "092c2874dc1b2060fa77a465a971acd4fdf87683",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1b12171533a9bb23cf6fba7262b479028b65e1e8",
              "lessThan": "135d542b97fa93e32c457d49d6e7b33ca7d05bae",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1b12171533a9bb23cf6fba7262b479028b65e1e8",
              "lessThan": "6b1f786ad85a0b63393b76f5e634deab1a73198c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1b12171533a9bb23cf6fba7262b479028b65e1e8",
              "lessThan": "7441ee8276641bddaf1cba7bb75ef9c1458ceb3b",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "include/linux/bpf_verifier.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": "6.12.111",
              "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/092c2874dc1b2060fa77a465a971acd4fdf87683",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/135d542b97fa93e32c457d49d6e7b33ca7d05bae",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6b1f786ad85a0b63393b76f5e634deab1a73198c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7441ee8276641bddaf1cba7bb75ef9c1458ceb3b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}