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

FKIE_CVE-2026-72122

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18
Summary
In the Linux kernel, the following vulnerability has been resolved: can: bcm: fix lockless bound/ifindex race and silent RX_SETUP failure bcm_sendmsg() reads bo->ifindex and checks bo->bound before taking lock_sock(), while bcm_notify(), bcm_connect() and bcm_release() all mutate both fields under that same lock. Because the lockless reads and the locked writes are unordered with respect to each other, a racing bcm_notify() (device unregister) or bcm_connect() (concurrent bind on another thread sharing the socket) can make bcm_sendmsg() observe an inconsistent combination, e.g. a stale bound=1 together with the now-cleared ifindex=0, silently turning a socket bound to a specific CAN interface into one that also matches "any" interface. Keep the lockless bo->bound check purely as a fast-path reject, and move the ifindex read (and a bo->bound re-check) into the locked section, where every writer already serializes. This removes the possibility of observing the two fields torn against each other, rather than trying to fix it with more READ_ONCE()/WRITE_ONCE() pairs on two independently updated fields. Annotate the now-purely-lockless bo->bound accesses consistently across all its write sites. Also fix bcm_rx_setup() silently returning success when the target device disappears concurrently instead of reporting -ENODEV, so a broken RX op is no longer left registered as if it had succeeded.
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/can/bcm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9e60c586faeaed80d55ab8ce2a4b8e56133bc395",
              "status": "affected",
              "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828",
              "versionType": "git"
            },
            {
              "lessThan": "ffa80a2af27c97453861a5128e537214a31cd18a",
              "status": "affected",
              "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828",
              "versionType": "git"
            },
            {
              "lessThan": "6bcc5cd247c2934373bc2a1cdf8bf12321169543",
              "status": "affected",
              "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828",
              "versionType": "git"
            },
            {
              "lessThan": "0f6f9f95294b4cbb26ba02209e893e3bd91237c3",
              "status": "affected",
              "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828",
              "versionType": "git"
            },
            {
              "lessThan": "b70f1a15533afeeec5d07f20bec3f3867ab1c7b6",
              "status": "affected",
              "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828",
              "versionType": "git"
            },
            {
              "lessThan": "35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d",
              "status": "affected",
              "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828",
              "versionType": "git"
            },
            {
              "lessThan": "b9c6ac6fb4e01b34575816066e5d3890a57b3c86",
              "status": "affected",
              "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828",
              "versionType": "git"
            },
            {
              "lessThan": "d9b091d9d22fee81ec53fb55d2032951993ceadb",
              "status": "affected",
              "version": "ffd980f976e7fd666c2e61bf8ab35107efd11828",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/can/bcm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.25"
            },
            {
              "lessThan": "2.6.25",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\ncan: bcm: fix lockless bound/ifindex race and silent RX_SETUP failure\n\nbcm_sendmsg() reads bo-\u003eifindex and checks bo-\u003ebound before taking\nlock_sock(), while bcm_notify(), bcm_connect() and bcm_release() all\nmutate both fields under that same lock. Because the lockless reads\nand the locked writes are unordered with respect to each other, a\nracing bcm_notify() (device unregister) or bcm_connect() (concurrent\nbind on another thread sharing the socket) can make bcm_sendmsg()\nobserve an inconsistent combination, e.g. a stale bound=1 together\nwith the now-cleared ifindex=0, silently turning a socket bound to a\nspecific CAN interface into one that also matches \"any\" interface.\n\nKeep the lockless bo-\u003ebound check purely as a fast-path reject, and\nmove the ifindex read (and a bo-\u003ebound re-check) into the locked\nsection, where every writer already serializes. This removes the\npossibility of observing the two fields torn against each other,\nrather than trying to fix it with more READ_ONCE()/WRITE_ONCE() pairs\non two independently updated fields. Annotate the now-purely-lockless\nbo-\u003ebound accesses consistently across all its write sites.\n\nAlso fix bcm_rx_setup() silently returning success when the target\ndevice disappears concurrently instead of reporting -ENODEV, so a\nbroken RX op is no longer left registered as if it had succeeded."
    }
  ],
  "id": "CVE-2026-72122",
  "lastModified": "2026-08-17T06:18:11.670",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "LOW",
          "baseScore": 7.3,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.5,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-15T06:21:29.437",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0f6f9f95294b4cbb26ba02209e893e3bd91237c3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/35f0ac19efb1a3f6c5e12c00e475a9ec2d9c3a6d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6bcc5cd247c2934373bc2a1cdf8bf12321169543"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9e60c586faeaed80d55ab8ce2a4b8e56133bc395"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b70f1a15533afeeec5d07f20bec3f3867ab1c7b6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b9c6ac6fb4e01b34575816066e5d3890a57b3c86"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d9b091d9d22fee81ec53fb55d2032951993ceadb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ffa80a2af27c97453861a5128e537214a31cd18a"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

Loading…