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CVE-2026-90088

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: Validate MTU in rfcomm_apply_pn() to prevent infinite loop rfcomm_apply_pn() accepts the MTU value from a remote PN (Parameter Negotiation) frame without checking for zero. When the remote peer sends an MTU of zero, d->mtu is set to 0. This causes the sendmsg path to enter an infinite loop when fragmenting data, as each fragment has size == min_t(size_t, len, 0) == 0, so the remaining length never decreases. The infinite allocation of zero-length skbs exhausts all system memory. Fix by clamping d->mtu to RFCOMM_DEFAULT_MTU when the negotiated value is zero, consistent with the initial value assigned in rfcomm_dlc_alloc().

Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-17 17:16:59.880000
Last modified
2026-10-19 09:18:57.763000
View original CVE JSON
{
  "id": "CVE-2026-90088",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-17T17:16:59.880",
  "lastModified": "2026-10-19T09:18:57.763",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: Validate MTU in rfcomm_apply_pn() to prevent infinite loop\n\nrfcomm_apply_pn() accepts the MTU value from a remote PN (Parameter\nNegotiation) frame without checking for zero. When the remote peer\nsends an MTU of zero, d->mtu is set to 0. This causes the sendmsg\npath to enter an infinite loop when fragmenting data, as each fragment\nhas size == min_t(size_t, len, 0) == 0, so the remaining length never\ndecreases. The infinite allocation of zero-length skbs exhausts all\nsystem memory.\n\nFix by clamping d->mtu to RFCOMM_DEFAULT_MTU when the negotiated\nvalue is zero, consistent with the initial value assigned in\nrfcomm_dlc_alloc()."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/bluetooth/rfcomm/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "e7c0aa45ae6c5a338661b23812bfcdef50bf3e96",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "cbc2962da99b6b89345267d3aa74b4b573340548",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "9b2e5f1928c99224345a9ed8c5dae5fc74964d6d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "fc4851ff8dfb505e9a19efcc286712132bbd178d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "f561e44261344adadf9d6a6dff31e3af9776d5c6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "aeee917a4878af95f0c63e18c5f22eaf6299c7b8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "3988cbb1be501dbff909a2ee024670e3c955a66d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "44c98fd082eafd49d55a8a4077ff488175b2fe24",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/bluetooth/rfcomm/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "2.6.12",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "2.6.12",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.270",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.221",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.188",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.110",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.52",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.6",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3988cbb1be501dbff909a2ee024670e3c955a66d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/44c98fd082eafd49d55a8a4077ff488175b2fe24",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9b2e5f1928c99224345a9ed8c5dae5fc74964d6d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/aeee917a4878af95f0c63e18c5f22eaf6299c7b8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cbc2962da99b6b89345267d3aa74b4b573340548",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e7c0aa45ae6c5a338661b23812bfcdef50bf3e96",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f561e44261344adadf9d6a6dff31e3af9776d5c6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/fc4851ff8dfb505e9a19efcc286712132bbd178d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}