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CVE-2026-80951 (GCVE-0-2026-80951)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:42 – Updated: 2026-09-14 11:59
VLAI
Title
i3c: master: svc: bound IBI payload to the requested max_payload_len
Summary
In the Linux kernel, the following vulnerability has been resolved: i3c: master: svc: bound IBI payload to the requested max_payload_len svc_i3c_master_handle_ibi() reads the IBI payload from the RX FIFO into the IBI slot. The loop is bounded by the hardware FIFO size (SVC_I3C_FIFO_SIZE), not by the slot size. slot->data points into the IBI pool, which i3c_generic_ibi_alloc_pool() sizes at max_payload_len per slot. svc_i3c_master_request_ibi() only rejects a max_payload_len larger than SVC_I3C_FIFO_SIZE, so a driver can request a smaller one. mctp-i3c requests 1. Each readsb() then copies the controller RXCOUNT bytes (up to 31) with no check against the slot size. A device that sends more bytes than the slot holds writes past slot->data, an out-of-bounds write into the IBI pool. Bound the loop by dev->ibi->max_payload_len and clamp each read to the space left in the slot, the same way dw-i3c does. A device can still send more than the requested payload. Flush the leftover bytes from the RX FIFO so they do not leak into the next transfer.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: dd3c52846d5954acd43f0e771689302f27dadc28 , < 7c099b0b292a68d0ef558527945dbfb756fbf893 (git)
Affected: dd3c52846d5954acd43f0e771689302f27dadc28 , < 7cc5ba756bc1cfffab9cb2695742f9f479dc73f7 (git)
Affected: dd3c52846d5954acd43f0e771689302f27dadc28 , < 35aa6730b8c5626b879a4e893fe664f59bf07d7f (git)
Affected: dd3c52846d5954acd43f0e771689302f27dadc28 , < f296a0d5907bf88314dfda67245f7f69d1552470 (git)
Affected: dd3c52846d5954acd43f0e771689302f27dadc28 , < 5697d779577e2786ff3348ae9b77020ac0cf0aab (git)
Affected: dd3c52846d5954acd43f0e771689302f27dadc28 , < aac3c5aababc7fb69d5bf5b0cc52d308574e3a8c (git)
Affected: dd3c52846d5954acd43f0e771689302f27dadc28 , < e2bda39d7f9f285ec803e200b5c1f17143d0b483 (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.12
Unaffected: 0 , < 5.12 (semver)
Unaffected: 5.15.221 , ≤ 5.15.* (semver)
Unaffected: 6.1.188 , ≤ 6.1.* (semver)
Unaffected: 6.6.157 , ≤ 6.6.* (semver)
Unaffected: 6.12.109 , ≤ 6.12.* (semver)
Unaffected: 6.18.50 , ≤ 6.18.* (semver)
Unaffected: 7.2.4 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ni3c: master: svc: bound IBI payload to the requested max_payload_len\n\nsvc_i3c_master_handle_ibi() reads the IBI payload from the RX FIFO into\nthe IBI slot. The loop is bounded by the hardware FIFO size\n(SVC_I3C_FIFO_SIZE), not by the slot size.\n\nslot-\u003edata points into the IBI pool, which i3c_generic_ibi_alloc_pool()\nsizes at max_payload_len per slot. svc_i3c_master_request_ibi() only\nrejects a max_payload_len larger than SVC_I3C_FIFO_SIZE, so a driver can\nrequest a smaller one. mctp-i3c requests 1. Each readsb() then copies the\ncontroller RXCOUNT bytes (up to 31) with no check against the slot size.\nA device that sends more bytes than the slot holds writes past\nslot-\u003edata, an out-of-bounds write into the IBI pool.\n\nBound the loop by dev-\u003eibi-\u003emax_payload_len and clamp each read to the\nspace left in the slot, the same way dw-i3c does. A device can still send\nmore than the requested payload. Flush the leftover bytes from the RX FIFO\nso they do not leak into the next transfer."
        }
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            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ni3c: master: svc: bound IBI payload to the requested max_payload_len\n\nsvc_i3c_master_handle_ibi() reads the IBI payload from the RX FIFO into\nthe IBI slot. The loop is bounded by the hardware FIFO size\n(SVC_I3C_FIFO_SIZE), not by the slot size.\n\nslot-\u003edata points into the IBI pool, which i3c_generic_ibi_alloc_pool()\nsizes at max_payload_len per slot. svc_i3c_master_request_ibi() only\nrejects a max_payload_len larger than SVC_I3C_FIFO_SIZE, so a driver can\nrequest a smaller one. mctp-i3c requests 1. Each readsb() then copies the\ncontroller RXCOUNT bytes (up to 31) with no check against the slot size.\nA device that sends more bytes than the slot holds writes past\nslot-\u003edata, an out-of-bounds write into the IBI pool.\n\nBound the loop by dev-\u003eibi-\u003emax_payload_len and clamp each read to the\nspace left in the slot, the same way dw-i3c does. A device can still send\nmore than the requested payload. Flush the leftover bytes from the RX FIFO\nso they do not leak into the next transfer."
          }
        ],
        "id": "CVE-2026-80951",
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        "metrics": {},
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      "current_release_date": "2026-09-14T17:14:14+00:00",
      "cve": "CVE-2026-80951",
      "id": "CVE-2026-80951",
      "initial_release_date": "2026-09-11T00:00:00+00:00",
      "product_status:known_affected": "185",
      "product_status:known_not_affected": "91",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: i3c: master: svc: bound IBI payload to the requested max_payload_len",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80951.json",
      "version": "3"
    },
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      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-15T01:05:39Z",
      "cve": "CVE-2026-80951",
      "id": "CVE-2026-80951",
      "initial_release_date": "2026-09-12T16:37:03Z",
      "product_status:known_affected": "126",
      "product_status:known_not_affected": "227",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80951",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80951.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.
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  • 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.


Detection rules are retrieved from Rulezet.


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