---
id: CVE-2026-72117
title: 'can: bcm: fix data race on rx_stamp/rx_ifindex in bcm_rx_handler()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  can: bcm: fix data race on rx_stamp/rx_ifindex in bcm_rx_handler()

  For an rx op subscribed on all interfaces (ifindex == 0), the same op
  is registered once in the shar…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 <
    b64f60c468d149aca22ea56bb842b9730215aaa5
  - >-
    Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 <
    c8a5d7cb095d3b12bd9dcf752d6ca0ff50872ac5
  - >-
    Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 <
    4b97410f4bba18d2ee2784c8e089104f387bc27c
  - >-
    Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 <
    5f246b96ab47523ec9b8ea870b5c567a3cb1eb1c
  - >-
    Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 <
    656ff69ef235699035e57d9e1ae417e62a38aa7f
  - >-
    Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 <
    136de17f38630307991c59aa7080012a99451783
  - >-
    Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 <
    c312b750bb5ac3348cfc85dab25e90937bd4d251
  - >-
    Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 <
    58fd6cbc8541216af1d7ed272ea7ac2b66d50fd8
  - Linux 2.6.25
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:51:45.682684Z'
published: '2026-08-15'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T16:55:20.494Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-72117'
references:
  - url: 'https://git.kernel.org/stable/c/b64f60c468d149aca22ea56bb842b9730215aaa5'
  - url: 'https://git.kernel.org/stable/c/c8a5d7cb095d3b12bd9dcf752d6ca0ff50872ac5'
  - url: 'https://git.kernel.org/stable/c/4b97410f4bba18d2ee2784c8e089104f387bc27c'
  - url: 'https://git.kernel.org/stable/c/5f246b96ab47523ec9b8ea870b5c567a3cb1eb1c'
  - url: 'https://git.kernel.org/stable/c/656ff69ef235699035e57d9e1ae417e62a38aa7f'
  - url: 'https://git.kernel.org/stable/c/136de17f38630307991c59aa7080012a99451783'
  - url: 'https://git.kernel.org/stable/c/c312b750bb5ac3348cfc85dab25e90937bd4d251'
  - url: 'https://git.kernel.org/stable/c/58fd6cbc8541216af1d7ed272ea7ac2b66d50fd8'
tags:
  - cve.org
epss: 0.00216
epssPercentile: 0.12147
ingestedAt: '2026-11-06T18:00:12.595Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

can: bcm: fix data race on rx_stamp/rx_ifindex in bcm_rx_handler()

For an rx op subscribed on all interfaces (ifindex == 0), the same op
is registered once in the shared per-netns wildcard filter list, so
bcm_rx_handler() can run concurrently on different CPUs for frames
arriving on different net devices.

op->rx_stamp and op->rx_ifindex were written before bcm_rx_update_lock was
taken, allowing concurrent writers to race each other - including a torn
store of the 64-bit rx_stamp on 32-bit platforms.

Beyond a torn store bcm_send_to_user() must report the timestamp/ifindex
of the very same frame whose content it is delivering. So the assignment
is placed in the same unbroken bcm_rx_update_lock section as the content
comparison.

As a side effect, the RTR-request frame feature (which never reach
bcm_send_to_user()) no longer updates rx_stamp/rx_ifindex, since only
the notification path needs them.

## Affected

- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < b64f60c468d149aca22ea56bb842b9730215aaa5`
- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < c8a5d7cb095d3b12bd9dcf752d6ca0ff50872ac5`
- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 4b97410f4bba18d2ee2784c8e089104f387bc27c`
- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 5f246b96ab47523ec9b8ea870b5c567a3cb1eb1c`
- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 656ff69ef235699035e57d9e1ae417e62a38aa7f`
- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 136de17f38630307991c59aa7080012a99451783`
- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < c312b750bb5ac3348cfc85dab25e90937bd4d251`
- `Linux >= ffd980f976e7fd666c2e61bf8ab35107efd11828 < 58fd6cbc8541216af1d7ed272ea7ac2b66d50fd8`
- `Linux 2.6.25`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.