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EUVD-2026-356359

European Vulnerability Database identifier assigned by ENISA

Reserved

2026-10-02 08:28

Assigner

ENISA

Alias of

a CVE record, shown under related vulnerabilities. This identifier carries no description, severity or references of its own: they belong to that CVE.

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{
  "assigner": "ENISA",
  "date_reserved": "2026-10-02T08:28:29.910876+00:00",
  "id": "EUVD-2026-356359"
}

CVE-2026-72121 (GCVE-0-2026-72121)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:52 – Updated: 2026-08-19 16:36

Title

can: bcm: add locking when updating filter and timer values

Summary

In the Linux kernel, the following vulnerability has been resolved: can: bcm: add locking when updating filter and timer values KCSAN detected a simultaneous access to timer values that can be overwritten in bcm_rx_setup() when updating timer and filter content while bcm_rx_handler(), bcm_rx_timeout_handler() or bcm_rx_thr_handler() run concurrently on incoming CAN traffic. Protect the timer (ival1/ival2/kt_ival1/kt_ival2/kt_lastmsg) and filter (nframes/flags/frames/last_frames) updates in bcm_rx_setup() with a new per-op bcm_rx_update_lock, taken with the matching scope in the RX handlers. memcpy_from_msg() is staged into a temporary buffer before the lock is taken, since it can sleep and must not run under a spinlock. hrtimer_cancel() is always called without bcm_rx_update_lock held, since bcm_rx_timeout_handler()/bcm_rx_thr_handler() take the same lock and a running callback would otherwise deadlock against the canceller. Also close a related race: bcm_rx_setup() cleared the RTR flag in the stored reply frame's can_id as a separate, unprotected step after the frame content was already installed, so a concurrent bcm_rx_handler() could transmit a stale reply with CAN_RTR_FLAG still set. Fold that normalization into the initial frame preparation instead (on the staged buffer for updates, directly on op->frames pre-registration for new ops), so the installed frame is always atomically self-consistent. bcm_rx_handler()'s RX_RTR_FRAME check now takes a lock-protected snapshot of op->flags before deciding whether to call bcm_can_tx(), but does not hold the lock across that call. Also take a lock-protected snapshot of the currframe in bcm_can_tx() to avoid partly overwrites by content updates in bcm_tx_setup(). Finally check if a TX_RESET_MULTI_IDX/SETTIMER might have reset op->currframe between the two locked sections in bcm_can_tx(). Omit calling hrtimer_forward() with zero interval in bcm_rx_thr_handler(). kt_ival2 may have been concurrently cleared by bcm_rx_setup() before it cancels this timer, so check kt_ival2 inside the bcm_rx_update_lock.

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root Scorecard

References

8 references

URL	Tags
https://git.kernel.org/stable/c/96994180bd7b248b0…
https://git.kernel.org/stable/c/caa8704a7f3cb7806…
https://git.kernel.org/stable/c/a7c369e7da8203e2b…
https://git.kernel.org/stable/c/a7eb6db1cd3f7b556…
https://git.kernel.org/stable/c/834cbca3b12e46887…
https://git.kernel.org/stable/c/19b1994069dd29478…
https://git.kernel.org/stable/c/fc9f5ee1b073bd233…
https://git.kernel.org/stable/c/749179c2e25b95d22…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 7595de7bc56e0e52b74e56c90f7e247bf626d628 , < 96994180bd7b248b0cc698afe926e23fc1bda59b (git) Affected: fbd8fdc2b218e979cfe422b139b8f74c12419d1f , < caa8704a7f3cb7806331596195385437126ecb3a (git) Affected: 2a437b86ac5a9893c902f30ef66815bf13587bf6 , < a7c369e7da8203e2b5be12bbcac7b9ab2ed5b658 (git) Affected: 76c84c3728178b2d38d5604e399dfe8b0752645e , < a7eb6db1cd3f7b556a301dc1265945ad112089f7 (git) Affected: cc55dd28c20a6611e30596019b3b2f636819a4c0 , < 834cbca3b12e46887f7a9b35f1981a888360ea4c (git) Affected: c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7 , < 19b1994069dd29478ba767de1f98f14a088198dc (git) Affected: c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7 , < fc9f5ee1b073bd233d9c604e338af4ebb42cbc33 (git) Affected: c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7 , < 749179c2e25b95d22499ed29096b3e02d6dfd2b4 (git) Affected: 8f1c022541bf5a923c8d6fa483112c15250f30a4 (git) Affected: c4e8a172501e677ebd8ea9d9161d97dc4df56fbd (git) Affected: 5.10.238 , < 5.10.265 (semver) Affected: 5.15.185 , < 5.15.216 (semver) Affected: 6.1.141 , < 6.1.183 (semver) Affected: 6.6.93 , < 6.6.148 (semver) Affected: 6.12.31 , < 6.12.101 (semver) Affected: 5.4.294 , < 5.5 (semver) Affected: 6.14.9 , < 6.15 (semver)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 5.10.265 , ≤ 5.10.* (semver) Unaffected: 5.15.216 , ≤ 5.15.* (semver) Unaffected: 6.1.183 , ≤ 6.1.* (semver) Unaffected: 6.6.148 , ≤ 6.6.* (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "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": "96994180bd7b248b0cc698afe926e23fc1bda59b",
              "status": "affected",
              "version": "7595de7bc56e0e52b74e56c90f7e247bf626d628",
              "versionType": "git"
            },
            {
              "lessThan": "caa8704a7f3cb7806331596195385437126ecb3a",
              "status": "affected",
              "version": "fbd8fdc2b218e979cfe422b139b8f74c12419d1f",
              "versionType": "git"
            },
            {
              "lessThan": "a7c369e7da8203e2b5be12bbcac7b9ab2ed5b658",
              "status": "affected",
              "version": "2a437b86ac5a9893c902f30ef66815bf13587bf6",
              "versionType": "git"
            },
            {
              "lessThan": "a7eb6db1cd3f7b556a301dc1265945ad112089f7",
              "status": "affected",
              "version": "76c84c3728178b2d38d5604e399dfe8b0752645e",
              "versionType": "git"
            },
            {
              "lessThan": "834cbca3b12e46887f7a9b35f1981a888360ea4c",
              "status": "affected",
              "version": "cc55dd28c20a6611e30596019b3b2f636819a4c0",
              "versionType": "git"
            },
            {
              "lessThan": "19b1994069dd29478ba767de1f98f14a088198dc",
              "status": "affected",
              "version": "c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7",
              "versionType": "git"
            },
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              "status": "affected",
              "version": "c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7",
              "versionType": "git"
            },
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              "status": "affected",
              "version": "c2aba69d0c36a496ab4f2e81e9c2b271f2693fd7",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8f1c022541bf5a923c8d6fa483112c15250f30a4",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "c4e8a172501e677ebd8ea9d9161d97dc4df56fbd",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.265",
              "status": "affected",
              "version": "5.10.238",
              "versionType": "semver"
            },
            {
              "lessThan": "5.15.216",
              "status": "affected",
              "version": "5.15.185",
              "versionType": "semver"
            },
            {
              "lessThan": "6.1.183",
              "status": "affected",
              "version": "6.1.141",
              "versionType": "semver"
            },
            {
              "lessThan": "6.6.148",
              "status": "affected",
              "version": "6.6.93",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12.101",
              "status": "affected",
              "version": "6.12.31",
              "versionType": "semver"
            },
            {
              "lessThan": "5.5",
              "status": "affected",
              "version": "5.4.294",
              "versionType": "semver"
            },
            {
              "lessThan": "6.15",
              "status": "affected",
              "version": "6.14.9",
              "versionType": "semver"
            }
          ]
        },
        {
          "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": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.265",
                  "versionStartIncluding": "5.10.238",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.216",
                  "versionStartIncluding": "5.15.185",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.183",
                  "versionStartIncluding": "6.1.141",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.148",
                  "versionStartIncluding": "6.6.93",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "6.12.31",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.4.294",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.14.9",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: add locking when updating filter and timer values\n\nKCSAN detected a simultaneous access to timer values that can be\noverwritten in bcm_rx_setup() when updating timer and filter content\nwhile bcm_rx_handler(), bcm_rx_timeout_handler() or bcm_rx_thr_handler()\nrun concurrently on incoming CAN traffic.\n\nProtect the timer (ival1/ival2/kt_ival1/kt_ival2/kt_lastmsg) and filter\n(nframes/flags/frames/last_frames) updates in bcm_rx_setup() with a new\nper-op bcm_rx_update_lock, taken with the matching scope in the RX\nhandlers. memcpy_from_msg() is staged into a temporary buffer before the\nlock is taken, since it can sleep and must not run under a spinlock.\n\nhrtimer_cancel() is always called without bcm_rx_update_lock held, since\nbcm_rx_timeout_handler()/bcm_rx_thr_handler() take the same lock and a\nrunning callback would otherwise deadlock against the canceller.\n\nAlso close a related race: bcm_rx_setup() cleared the RTR flag in the\nstored reply frame\u0027s can_id as a separate, unprotected step after the\nframe content was already installed, so a concurrent bcm_rx_handler()\ncould transmit a stale reply with CAN_RTR_FLAG still set. Fold that\nnormalization into the initial frame preparation instead (on the staged\nbuffer for updates, directly on op-\u003eframes pre-registration for new\nops), so the installed frame is always atomically self-consistent.\n\nbcm_rx_handler()\u0027s RX_RTR_FRAME check now takes a lock-protected\nsnapshot of op-\u003eflags before deciding whether to call bcm_can_tx(),\nbut does not hold the lock across that call.\n\nAlso take a lock-protected snapshot of the currframe in bcm_can_tx()\nto avoid partly overwrites by content updates in bcm_tx_setup().\nFinally check if a TX_RESET_MULTI_IDX/SETTIMER might have reset\nop-\u003ecurrframe between the two locked sections in bcm_can_tx().\n\nOmit calling hrtimer_forward() with zero interval in bcm_rx_thr_handler().\nkt_ival2 may have been concurrently cleared by bcm_rx_setup() before it\ncancels this timer, so check kt_ival2 inside the bcm_rx_update_lock."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:A - The race is driven by concurrent CAN frame reception in bcm_rx_handler()/timer callbacks on a shared CAN segment (automotive OBD/ECU bus, factory controllers, CAN-USB adapters), an adjacent broadcast medium comparable to Bluetooth/WiFi segment access.\nAC:L - An attacker controls both race sides by flooding RX_SETUP via sendmsg while concurrently injecting matching CAN frames or armed timers; syzbot reliably reproduced the KCSAN race without timing conditions beyond attacker control.\nPR:N - CAN_BCM sockets impose no capability checks in can_create()/bcm_sendmsg(), and a bus participant can trigger the RX handler path without any Linux credentials while racing BCM configuration updates from local services.\nUI:N - Exploitation requires no victim interaction beyond normal background CAN/BCM activity on systems that already use the Broadcast Manager for monitoring or diagnostics.\nS:U - Impact is confined to kernel memory corruption and privilege boundaries within the same host; this is not a VM escape, IOMMU bypass, or cross-authority sandbox breakout.\nC:H - Unlocked concurrent updates to nframes/flags/frames/last_frames permit torn reads and out-of-bounds accesses in handler loops and timeout memset, matching the prior BCM race class that produced KASAN slab-out-of-bounds reads.\nI:H - Partial overwrites of op-\u003eframes during bcm_can_tx(), stale RTR replies transmitted on the bus, and size-mismatched memset/memcpy against concurrently shrinking buffers enable arbitrary CAN injection and kernel heap corruption.\nA:H - Concurrent timer corruption (hrtimer_forward with zero kt_ival2), torn structure fields, and heap corruption from racing memset/copy operations can cause kernel oops, panic, or sustained denial of service on CAN-equipped systems."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-19T16:36:16.520Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/96994180bd7b248b0cc698afe926e23fc1bda59b"
        },
        {
          "url": "https://git.kernel.org/stable/c/caa8704a7f3cb7806331596195385437126ecb3a"
        },
        {
          "url": "https://git.kernel.org/stable/c/a7c369e7da8203e2b5be12bbcac7b9ab2ed5b658"
        },
        {
          "url": "https://git.kernel.org/stable/c/a7eb6db1cd3f7b556a301dc1265945ad112089f7"
        },
        {
          "url": "https://git.kernel.org/stable/c/834cbca3b12e46887f7a9b35f1981a888360ea4c"
        },
        {
          "url": "https://git.kernel.org/stable/c/19b1994069dd29478ba767de1f98f14a088198dc"
        },
        {
          "url": "https://git.kernel.org/stable/c/fc9f5ee1b073bd233d9c604e338af4ebb42cbc33"
        },
        {
          "url": "https://git.kernel.org/stable/c/749179c2e25b95d22499ed29096b3e02d6dfd2b4"
        }
      ],
      "title": "can: bcm: add locking when updating filter and timer values",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72121",
    "datePublished": "2026-08-15T05:52:59.959Z",
    "dateReserved": "2026-08-09T03:40:39.907Z",
    "dateUpdated": "2026-08-19T16:36:16.520Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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EUVD-2026-356359

CVE-2026-72121 (GCVE-0-2026-72121)

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Nomenclature

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