CVE-2026-90217 (GCVE-0-2026-90217)
Vulnerability from cvelistv5
Published
2026-09-17 16:07
Modified
2026-10-21 12:50
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Compare iterator types during state pruning An iterator stack slot can be MEM_RCU or PTR_UNTRUSTED. These states must not be equal, or the verifier can prune an unsafe path. Compare the pointer type for STACK_ITER slots.
References
Impacted products
Vendor Product Version
Linux Linux Version: dfab99df147b0d364f0c199f832ff2aedfb2265a
Version: dfab99df147b0d364f0c199f832ff2aedfb2265a
Version: dfab99df147b0d364f0c199f832ff2aedfb2265a
Version: dfab99df147b0d364f0c199f832ff2aedfb2265a
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/states.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "86bbaf9e6e4fa6c0dfb352e9e11fae328069233a",
              "status": "affected",
              "version": "dfab99df147b0d364f0c199f832ff2aedfb2265a",
              "versionType": "git"
            },
            {
              "lessThan": "e4ab436d5ba61e4910fd49d24bb64ddb34d493d6",
              "status": "affected",
              "version": "dfab99df147b0d364f0c199f832ff2aedfb2265a",
              "versionType": "git"
            },
            {
              "lessThan": "6424b9cde9edc7f2098115bbfd1ee3d84a958380",
              "status": "affected",
              "version": "dfab99df147b0d364f0c199f832ff2aedfb2265a",
              "versionType": "git"
            },
            {
              "lessThan": "83608e303b95d07afba1c15da0b5d9e513c2f15a",
              "status": "affected",
              "version": "dfab99df147b0d364f0c199f832ff2aedfb2265a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/states.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.114",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.57",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Compare iterator types during state pruning\n\nAn iterator stack slot can be MEM_RCU or PTR_UNTRUSTED. These states\nmust not be equal, or the verifier can prune an unsafe path.\n\nCompare the pointer type for STACK_ITER slots."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The attacker-controlled input is the BPF instruction stream copied in bpf_prog_load() from bpf(2) BPF_PROG_LOAD (__sys_bpf). bpf_check() then stacksafe() treats STACK_ITER slots with MEM_RCU and PTR_UNTRUSTED as equal; that bytecode is local syscall input, not a remote protocol payload.\nAC:L - The attacker authors both verifier paths as in iter_tasks_rcu_state_pruning: bpf_iter_task_new under bpf_rcu_read_lock, then a bpf_get_prandom_u32 branch that nested-lock/unlock (MEM_RCU) or unlock/relock (PTR_UNTRUSTED) before bpf_iter_task_next. Both sides and the branch are attacker-controlled; no victim timing is required.\nPR:L - add_subprog_and_kfunc() rejects kfunc calls unless env-\u003ebpf_capable. bpf_iter_task_new and bpf_iter_css_new are kfuncs; BPF_PROG_TYPE_SYSCALL (always sleepable) needs only bpf_token_capable(CAP_BPF). bpf_token_capable() uses ns_capable() on a delegated token userns, so this is not init-namespace root.\nUI:N - The attacker loads the crafted sleepable program with BPF_PROG_LOAD and executes it via BPF_PROG_TEST_RUN (bpf_prog_test_run_syscall) or by attaching their own fentry.s; no other user must mount a filesystem, open a file, or cooperate.\nS:U - A pruned bpf_iter_task_next() walks host task_struct lists in the same kernel that loaded the program. That is in-kernel use-after-free and privilege escalation, not a KVM/Xen guest-to-host escape or IOMMU bypass.\nC:H - After the pruned unlock/relock gap, bpf_iter_task_next() returns kit-\u003epos from bpf_iter_task_kern, a task_struct * that may already have been RCU-freed. The program can read BTF fields of that dangling pointer, so the UAF is an arbitrary kernel disclosure.\nI:H - bpf_iter_task_next() then calls next_task()/__next_thread() (list_entry_rcu on tasks.next and thread_node) using the dangling kit-\u003epos. Walking attacker-reclaimed task_struct list nodes is a kernel write primitive; UAF and iterator type confusion are Integrity High.\nA:H - Using the untrusted STACK_ITER after the RCU gap makes next_task() or css_next_descendant_*() dereference a freed task_struct or cgroup_subsys_state, causing a kernel oops or panic even when the UAF is not fully exploited."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:50:30.155Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/86bbaf9e6e4fa6c0dfb352e9e11fae328069233a"
        },
        {
          "url": "https://git.kernel.org/stable/c/e4ab436d5ba61e4910fd49d24bb64ddb34d493d6"
        },
        {
          "url": "https://git.kernel.org/stable/c/6424b9cde9edc7f2098115bbfd1ee3d84a958380"
        },
        {
          "url": "https://git.kernel.org/stable/c/83608e303b95d07afba1c15da0b5d9e513c2f15a"
        }
      ],
      "title": "bpf: Compare iterator types during state pruning",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90217",
    "datePublished": "2026-09-17T16:07:29.409Z",
    "dateReserved": "2026-09-11T19:38:34.793Z",
    "dateUpdated": "2026-10-21T12:50:30.155Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.