Vulnerability-Lookup

GHSA-HW45-3JC9-W8MR

Vulnerability from github – Published: 2026-10-18 18:32 – Updated: 2026-10-18 18:32

Details

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

bpf: Wait for an RCU tasks grace period before freeing trampoline progs

When a prog is detached from a trampoline, it is freed after an RCU grace period, or an RCU tasks trace one if it is sleepable. This covers the tasks that are running the prog, since the prog's enter helper takes the matching read lock before the prog is called. On a preemptible kernel, it doesn't cover a task that was preempted in the trampoline just before the enter helper. That task holds no lock yet, and it calls the prog after it was freed:

BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_enter_recur+0x3a5/0x3f0 Read of size 8 at addr ffffc90000055040 by task candidate/110 CPU: 1 UID: 0 PID: 110 Comm: candidate Not tainted 7.3.0-rc2-00014-g15071f2a1263-dirty #2 PREEMPT(full) Call Trace: __bpf_prog_enter_recur+0x3a5/0x3f0 bpf_trampoline_6442509193+0x37/0xf1 __x64_sys_futex+0x9/0x410 do_syscall_64+0xb0/0x530 ...

Wait for an RCU tasks grace period before the existing one when freeing a prog that was linked to a trampoline. An RCU tasks grace period only ends once the tasks that were preempted have run again, and bpf_tramp_image_put() already relies on it to free the image. It doesn't wait for tasks that sleep in the trampoline, the next commit takes care of those.

Only progs that were linked to a trampoline can be called this way, so bpf_trampoline_add_prog() marks them and other progs are still freed as before.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-98800"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-18T16:17:34Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Wait for an RCU tasks grace period before freeing trampoline progs\n\nWhen a prog is detached from a trampoline, it is freed after an RCU\ngrace period, or an RCU tasks trace one if it is sleepable. This covers\nthe tasks that are running the prog, since the prog\u0027s enter helper takes\nthe matching read lock before the prog is called. On a preemptible\nkernel, it doesn\u0027t cover a task that was preempted in the trampoline\njust before the enter helper. That task holds no lock yet, and it calls\nthe prog after it was freed:\n\n  BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_enter_recur+0x3a5/0x3f0\n  Read of size 8 at addr ffffc90000055040 by task candidate/110\n  CPU: 1 UID: 0 PID: 110 Comm: candidate Not tainted 7.3.0-rc2-00014-g15071f2a1263-dirty #2 PREEMPT(full)\n  Call Trace:\n   \u003cTASK\u003e\n   __bpf_prog_enter_recur+0x3a5/0x3f0\n   bpf_trampoline_6442509193+0x37/0xf1\n   __x64_sys_futex+0x9/0x410\n   do_syscall_64+0xb0/0x530\n   ...\n\nWait for an RCU tasks grace period before the existing one when freeing\na prog that was linked to a trampoline. An RCU tasks grace period only\nends once the tasks that were preempted have run again, and\nbpf_tramp_image_put() already relies on it to free the image. It doesn\u0027t\nwait for tasks that sleep in the trampoline, the next commit takes care\nof those.\n\nOnly progs that were linked to a trampoline can be called this way, so\nbpf_trampoline_add_prog() marks them and other progs are still freed as\nbefore.",
  "id": "GHSA-hw45-3jc9-w8mr",
  "modified": "2026-10-18T18:32:04Z",
  "published": "2026-10-18T18:32:04Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98800"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0fb5751a6e411b1b466c06e50021818d9391df98"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/40955f6512a03f0e046f5256b0706b26ba191018"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-98800 (GCVE-0-2026-98800)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:48 – Updated: 2026-10-19 09:25

Title

bpf: Wait for an RCU tasks grace period before freeing trampoline progs

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Wait for an RCU tasks grace period before freeing trampoline progs When a prog is detached from a trampoline, it is freed after an RCU grace period, or an RCU tasks trace one if it is sleepable. This covers the tasks that are running the prog, since the prog's enter helper takes the matching read lock before the prog is called. On a preemptible kernel, it doesn't cover a task that was preempted in the trampoline just before the enter helper. That task holds no lock yet, and it calls the prog after it was freed: BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_enter_recur+0x3a5/0x3f0 Read of size 8 at addr ffffc90000055040 by task candidate/110 CPU: 1 UID: 0 PID: 110 Comm: candidate Not tainted 7.3.0-rc2-00014-g15071f2a1263-dirty #2 PREEMPT(full) Call Trace: <TASK> __bpf_prog_enter_recur+0x3a5/0x3f0 bpf_trampoline_6442509193+0x37/0xf1 __x64_sys_futex+0x9/0x410 do_syscall_64+0xb0/0x530 ... Wait for an RCU tasks grace period before the existing one when freeing a prog that was linked to a trampoline. An RCU tasks grace period only ends once the tasks that were preempted have run again, and bpf_tramp_image_put() already relies on it to free the image. It doesn't wait for tasks that sleep in the trampoline, the next commit takes care of those. Only progs that were linked to a trampoline can be called this way, so bpf_trampoline_add_prog() marks them and other progs are still freed as before.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6820 records in the last 180 days details

References

2 references

URL	Tags
https://git.kernel.org/stable/c/40955f6512a03f0e0…
https://git.kernel.org/stable/c/0fb5751a6e411b1b4…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e21aa341785c679dd409c8cb71f864c00fe6c463 , < 40955f6512a03f0e046f5256b0706b26ba191018 (git) Affected: e21aa341785c679dd409c8cb71f864c00fe6c463 , < 0fb5751a6e411b1b466c06e50021818d9391df98 (git) Affected: e21d2b92354b3cd25dd774ebb0f0e52ff04a7861 (git) Affected: 85d177f56e5256e14b74a65940f981f6e3e8bb32 (git) Affected: 5.10.28 , < 5.11 (semver) Affected: 5.11.11 , < 5.12 (semver)
Linux	Linux	Affected: 5.12 Unaffected: 0 , < 5.12 (semver) Unaffected: 7.2.10 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
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          "programFiles": [
            "include/linux/bpf.h",
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "40955f6512a03f0e046f5256b0706b26ba191018",
              "status": "affected",
              "version": "e21aa341785c679dd409c8cb71f864c00fe6c463",
              "versionType": "git"
            },
            {
              "lessThan": "0fb5751a6e411b1b466c06e50021818d9391df98",
              "status": "affected",
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            },
            {
              "status": "affected",
              "version": "85d177f56e5256e14b74a65940f981f6e3e8bb32",
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              "version": "5.10.28",
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            },
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            }
          ]
        },
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            "kernel/bpf/syscall.c",
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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              "status": "unaffected",
              "version": "0",
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            },
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            },
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              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "5.12",
                  "vulnerable": true
                },
                {
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Wait for an RCU tasks grace period before freeing trampoline progs\n\nWhen a prog is detached from a trampoline, it is freed after an RCU\ngrace period, or an RCU tasks trace one if it is sleepable. This covers\nthe tasks that are running the prog, since the prog\u0027s enter helper takes\nthe matching read lock before the prog is called. On a preemptible\nkernel, it doesn\u0027t cover a task that was preempted in the trampoline\njust before the enter helper. That task holds no lock yet, and it calls\nthe prog after it was freed:\n\n  BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_enter_recur+0x3a5/0x3f0\n  Read of size 8 at addr ffffc90000055040 by task candidate/110\n  CPU: 1 UID: 0 PID: 110 Comm: candidate Not tainted 7.3.0-rc2-00014-g15071f2a1263-dirty #2 PREEMPT(full)\n  Call Trace:\n   \u003cTASK\u003e\n   __bpf_prog_enter_recur+0x3a5/0x3f0\n   bpf_trampoline_6442509193+0x37/0xf1\n   __x64_sys_futex+0x9/0x410\n   do_syscall_64+0xb0/0x530\n   ...\n\nWait for an RCU tasks grace period before the existing one when freeing\na prog that was linked to a trampoline. An RCU tasks grace period only\nends once the tasks that were preempted have run again, and\nbpf_tramp_image_put() already relies on it to free the image. It doesn\u0027t\nwait for tasks that sleep in the trampoline, the next commit takes care\nof those.\n\nOnly progs that were linked to a trampoline can be called this way, so\nbpf_trampoline_add_prog() marks them and other progs are still freed as\nbefore."
        }
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        "dateUpdated": "2026-10-19T09:25:53.724Z",
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    "datePublished": "2026-10-18T15:48:46.223Z",
    "dateReserved": "2026-09-25T10:25:14.370Z",
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    "state": "PUBLISHED"
  },
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}

Sightings

Author	Source	Type	Date	Other

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.

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