CVE-2026-72122

Technical Description

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

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