CVE-2026-72113

Technical Description

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

can: bcm: add missing device refcount for CAN filter removal

sashiko-bot remarked a problem with a concurrent device unregistration

in isotp.c which also is present in the bcm.c code. A former fix for raw.c

commit c275a176e4b6 ("can: raw: add missing refcount for memory leak fix")

introduced a netdevice_tracker which solves the issue for bcm.c too.

bcm_release(), bcm_delete_rx_op() and bcm_notifier() relied on

dev_get_by_index(ifindex) to re-find the device for an rx_op before

unregistering its filter. If a concurrent NETDEV_UNREGISTER has already

unlisted the device from the ifindex table, that lookup fails and

can_rx_unregister() is silently skipped, leaving a stale CAN filter

pointing at the soon-to-be-freed bcm_op/socket.

Hold a netdev_hold()/netdev_put() tracked reference on op->rx_reg_dev

from the moment the rx filter is registered in bcm_rx_setup() until it

is unregistered in bcm_rx_unreg(), and use that ref

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References