GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-80998 (GCVE-0-2026-80998)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:42 – Updated: 2026-09-13 06:29
VLAI
Title
net: bnxt: ring the doorbell when SW USO exits early
Summary
In the Linux kernel, the following vulnerability has been resolved: net: bnxt: ring the doorbell when SW USO exits early When a burst of packets is handed down to the driver, the driver defers the doorbell to the end by setting txr->kick_pending = 1. The normal TX path handles this, but the SW USO path can miss it if it returns early. If bnxt_sw_udp_gso_xmit runs but returns early with NETDEV_TX_BUSY and txr->kick_pending was previously set to 1, then the TX queue can stall because the driver wrote some BDs but never wrote the doorbell. The device won't know to do the TX which would generate the completion that would wake the queue back up. Simplify bnxt_sw_udp_gso_xmit to set txr->kick_pending in its success case and check the flag on return. The added check after bnxt_sw_udp_gso_xmit returns ensures that any pending doorbells are written handling both successful USO and any early returns, which prevents the TX queue stall mentioned above. This TX queue stall was observed on a production system with a netdev TX watchdog informing about the queue stall.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: cc5d90667db81474ed7a92a1b2fa3daec5559307 , < 48d1c9665db6e3d4aeca62eb669377162ebc6fdf (git)
Affected: cc5d90667db81474ed7a92a1b2fa3daec5559307 , < 4e15e89faac9f308baeb01f46c13a051814d2449 (git)
guessed Create a notification for this product.
Linux Linux Affected: 7.1
Unaffected: 0 , < 7.1 (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
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/broadcom/bnxt/bnxt.c",
            "drivers/net/ethernet/broadcom/bnxt/bnxt_gso.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "48d1c9665db6e3d4aeca62eb669377162ebc6fdf",
              "status": "affected",
              "version": "cc5d90667db81474ed7a92a1b2fa3daec5559307",
              "versionType": "git"
            },
            {
              "lessThan": "4e15e89faac9f308baeb01f46c13a051814d2449",
              "status": "affected",
              "version": "cc5d90667db81474ed7a92a1b2fa3daec5559307",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/broadcom/bnxt/bnxt.c",
            "drivers/net/ethernet/broadcom/bnxt/bnxt_gso.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bnxt: ring the doorbell when SW USO exits early\n\nWhen a burst of packets is handed down to the driver, the driver defers\nthe doorbell to the end by setting txr-\u003ekick_pending = 1. The normal TX\npath handles this, but the SW USO path can miss it if it returns\nearly.\n\nIf bnxt_sw_udp_gso_xmit runs but returns early with NETDEV_TX_BUSY and\ntxr-\u003ekick_pending was previously set to 1, then the TX queue can\nstall because the driver wrote some BDs but never wrote the doorbell.\nThe device won\u0027t know to do the TX which would generate the completion\nthat would wake the queue back up.\n\nSimplify bnxt_sw_udp_gso_xmit to set txr-\u003ekick_pending in its success\ncase and check the flag on return. The added check after\nbnxt_sw_udp_gso_xmit returns ensures that any pending doorbells are\nwritten handling both successful USO and any early returns, which\nprevents the TX queue stall mentioned above.\n\nThis TX queue stall was observed on a production system with a netdev TX\nwatchdog informing about the queue stall."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The flaw is in bnxt_start_xmit (ndo_start_xmit) on Broadcom NetXtreme NICs; a remote attacker can induce software UDP GSO egress via QUIC/HTTP3 replies, forwarded or bridged tenant flows, or hypervisor uplink transmit on internet-facing cloud and datacenter servers without local shell access.\nAC:L - An attacker can drive a TX burst that sets kick_pending and then a UDP GSO skb that returns NETDEV_TX_BUSY by flooding mixed-size UDP/GSO traffic until the ring or inline header slots are full; this is a deterministic missed-doorbell logic bug, not a race or layout condition outside attacker control.\nPR:N - Reaching bnxt_sw_udp_gso_xmit requires only the ability to cause UDP GSO packets to egress an already-up bnxt interface; unauthenticated QUIC/UDP service traffic and forwarded packets hit this path with no local account, capability, or CAP_NET_ADMIN.\nUI:N - Exploitation needs only attacker-generated network traffic that produces UDP GSO transmit on a live bnxt uplink; no victim action such as mounting a filesystem or opening a file is required.\nS:U - The missed doorbell stalls and resets transmit queues inside the same kernel/netdev authority and does not cross a VM, IOMMU, or sandbox security boundary.\nC:N - The defect only skips a TX doorbell write after an early NETDEV_TX_BUSY or drop return from software USO; it does not read packet or kernel memory and yields no information-disclosure primitive.\nI:N - No buffer overflow, use-after-free, or other memory corruption occurs; previously posted buffer descriptors are simply never kicked, so there is no unauthorized modification or control-flow hijack.\nA:H - Skipping the doorbell leaves posted TX descriptors unprocessed so completions never arrive, the queue stays stopped, and the netdev watchdog calls bnxt_tx_timeout() and bnxt_reset_task(); repeating the pattern sustains a complete loss of connectivity on the affected NIC."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-13T06:29:01.300Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/48d1c9665db6e3d4aeca62eb669377162ebc6fdf"
        },
        {
          "url": "https://git.kernel.org/stable/c/4e15e89faac9f308baeb01f46c13a051814d2449"
        }
      ],
      "title": "net: bnxt: ring the doorbell when SW USO exits early",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80998",
    "datePublished": "2026-09-11T19:42:52.861Z",
    "dateReserved": "2026-08-26T14:34:25.812Z",
    "dateUpdated": "2026-09-13T06:29:01.300Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-80998",
      "date": "2026-09-17",
      "epss": "0.00467",
      "percentile": "0.39458"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "drivers/net/ethernet/broadcom/bnxt/bnxt.c",
                  "drivers/net/ethernet/broadcom/bnxt/bnxt_gso.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "48d1c9665db6e3d4aeca62eb669377162ebc6fdf",
                    "status": "affected",
                    "version": "cc5d90667db81474ed7a92a1b2fa3daec5559307",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "4e15e89faac9f308baeb01f46c13a051814d2449",
                    "status": "affected",
                    "version": "cc5d90667db81474ed7a92a1b2fa3daec5559307",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "drivers/net/ethernet/broadcom/bnxt/bnxt.c",
                  "drivers/net/ethernet/broadcom/bnxt/bnxt_gso.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "7.1"
                  },
                  {
                    "lessThan": "7.1",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.2.*",
                    "status": "unaffected",
                    "version": "7.2.4",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3-rc1",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bnxt: ring the doorbell when SW USO exits early\n\nWhen a burst of packets is handed down to the driver, the driver defers\nthe doorbell to the end by setting txr-\u003ekick_pending = 1. The normal TX\npath handles this, but the SW USO path can miss it if it returns\nearly.\n\nIf bnxt_sw_udp_gso_xmit runs but returns early with NETDEV_TX_BUSY and\ntxr-\u003ekick_pending was previously set to 1, then the TX queue can\nstall because the driver wrote some BDs but never wrote the doorbell.\nThe device won\u0027t know to do the TX which would generate the completion\nthat would wake the queue back up.\n\nSimplify bnxt_sw_udp_gso_xmit to set txr-\u003ekick_pending in its success\ncase and check the flag on return. The added check after\nbnxt_sw_udp_gso_xmit returns ensures that any pending doorbells are\nwritten handling both successful USO and any early returns, which\nprevents the TX queue stall mentioned above.\n\nThis TX queue stall was observed on a production system with a netdev TX\nwatchdog informing about the queue stall."
          }
        ],
        "id": "CVE-2026-80998",
        "lastModified": "2026-09-13T07:17:06.483",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 3.6,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-09-11T20:19:06.873",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/48d1c9665db6e3d4aeca62eb669377162ebc6fdf"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/4e15e89faac9f308baeb01f46c13a051814d2449"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-14T20:26:53+00:00",
      "cve": "CVE-2026-80998",
      "id": "CVE-2026-80998",
      "initial_release_date": "2026-09-11T00:00:00+00:00",
      "product_status:known_not_affected": "276",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net: bnxt: ring the doorbell when SW USO exits early",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80998.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-15T01:04:22Z",
      "cve": "CVE-2026-80998",
      "id": "CVE-2026-80998",
      "initial_release_date": "2026-09-15T01:04:22Z",
      "product_status:known_not_affected": "353",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80998",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80998.json",
      "version": "2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.

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.


Detection rules are retrieved from Rulezet.


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.