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CVE-2026-80811 (GCVE-0-2026-80811)

Vulnerability from cvelistv5 – Published: 2026-09-04 15:13 – Updated: 2026-09-04 15:13
VLAI
Title
io_uring/cmd: fix iovec leak when the async cmd is not recycled
Summary
In the Linux kernel, the following vulnerability has been resolved: io_uring/cmd: fix iovec leak when the async cmd is not recycled An io_async_cmd carries an iovec array in ->vec.iovec, allocated when the vec has to grow and kept across recycling through ctx->cmd_cache. On two paths nothing frees it and io_clean_op()'s kfree(req->async_data) drops the io_async_cmd without it. io_req_uring_cleanup() clears the async data flags only when io_alloc_cache_put() succeeds, and the cache holds IO_ALLOC_CACHE_MAX == 128 entries, so once it is full the put fails and the vec is left behind. An NVMe passthrough workload gets there without doing anything unusual: nvme_uring_cmd_io() returns -EIOCBQUEUED, so the io_async_cmd stays attached for the lifetime of the command and the live object count tracks the queue depth. Above 128 the puts start failing. ->cleanup is the last chance to free an inherited vec, since io_req_uring_cleanup() returns early for an io-wq issued command and is not called at all for one completed without ever being issued. But io_clean_op() calls ->cleanup only if REQ_F_NEED_CLEANUP is set, and for uring_cmd that happens only where the vec has to grow, so a command reusing a large enough cached vec never sets it. io_rw_alloc_async() and io_msg_alloc_async() flag an inherited vec for exactly this reason; io_uring_cmd_prep() does not. Flag an inherited vec in io_uring_cmd_prep(), and free the vec when the cache put fails, as io_req_rw_cleanup() does. The leak is invisible under KASAN, where io_alloc_cache_vec_kasan() frees the vec unconditionally.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 3a4689ac109f18f23ea0d0c1c79e055142796858 , < b6a768aa975b9ca81b92f028bdd975d1f8237894 (git)
Affected: 3a4689ac109f18f23ea0d0c1c79e055142796858 , < b290de4d16d75b6c1ef42025b47f5d94eb1ec09f (git)
Affected: 3a4689ac109f18f23ea0d0c1c79e055142796858 , < 7068d3587a64a24943a7c9e232976da2c9e0e303 (git)
Affected: 3a4689ac109f18f23ea0d0c1c79e055142796858 , < bb34ae5da3365699d53a756f4c96b6ea9f8ba0c1 (git)
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Linux Linux Affected: 6.15
Unaffected: 0 , < 6.15 (semver)
Unaffected: 6.18.47 , ≤ 6.18.* (semver)
Unaffected: 7.1.11 , ≤ 7.1.* (semver)
Unaffected: 7.2.1 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
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          "product": "Linux",
          "programFiles": [
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/cmd: fix iovec leak when the async cmd is not recycled\n\nAn io_async_cmd carries an iovec array in -\u003evec.iovec, allocated when the\nvec has to grow and kept across recycling through ctx-\u003ecmd_cache.  On two\npaths nothing frees it and io_clean_op()\u0027s kfree(req-\u003easync_data) drops\nthe io_async_cmd without it.\n\nio_req_uring_cleanup() clears the async data flags only when\nio_alloc_cache_put() succeeds, and the cache holds IO_ALLOC_CACHE_MAX ==\n128 entries, so once it is full the put fails and the vec is left behind.\nAn NVMe passthrough workload gets there without doing anything unusual:\nnvme_uring_cmd_io() returns -EIOCBQUEUED, so the io_async_cmd stays\nattached for the lifetime of the command and the live object count tracks\nthe queue depth.  Above 128 the puts start failing.\n\n-\u003ecleanup is the last chance to free an inherited vec, since\nio_req_uring_cleanup() returns early for an io-wq issued command and is\nnot called at all for one completed without ever being issued.  But\nio_clean_op() calls -\u003ecleanup only if REQ_F_NEED_CLEANUP is set, and for\nuring_cmd that happens only where the vec has to grow, so a command\nreusing a large enough cached vec never sets it.  io_rw_alloc_async() and\nio_msg_alloc_async() flag an inherited vec for exactly this reason;\nio_uring_cmd_prep() does not.\n\nFlag an inherited vec in io_uring_cmd_prep(), and free the vec when the\ncache put fails, as io_req_rw_cleanup() does.\n\nThe leak is invisible under KASAN, where io_alloc_cache_vec_kasan() frees\nthe vec unconditionally."
        }
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      "providerMetadata": {
        "dateUpdated": "2026-09-04T15:13:31.761Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/7068d3587a64a24943a7c9e232976da2c9e0e303"
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        {
          "url": "https://git.kernel.org/stable/c/bb34ae5da3365699d53a756f4c96b6ea9f8ba0c1"
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      ],
      "title": "io_uring/cmd: fix iovec leak when the async cmd is not recycled",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80811",
    "datePublished": "2026-09-04T15:13:31.761Z",
    "dateReserved": "2026-08-26T14:34:25.794Z",
    "dateUpdated": "2026-09-04T15:13:31.761Z",
    "state": "PUBLISHED"
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    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-08T17:17:08Z",
      "cve": "CVE-2026-80811",
      "id": "CVE-2026-80811",
      "initial_release_date": "2026-09-05T00:26:56Z",
      "product_status:known_not_affected": "353",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80811",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80811.json",
      "version": "4"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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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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Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.