CVE-2026-72116
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
In the Linux kernel, the CAN BCM module has an issue with stale RX/TX ops after device removal. For RX, an RX_SETUP update could skip re-registering the filter when the device was removed, leaving the filter inactive. For TX, bcm_notify() did not handle tx_ops, leading to an endless timer re-arming and potential injection into a later reused ifindex.
Risk Assessment
This can lead to malfunctioning CAN systems, including sending frames to inappropriate interfaces or inactive filters.
Recommendation
Apply the kernel patch that adds re-registration for RX and timer cancellation for TX after device removal.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: can: bcm: fix stale rx/tx ops after device removal RX: an RX_SETUP update(!) for an existing op skipped can_rx_register() unconditionally, even when a concurrent NETDEV_UNREGISTER had already torn down its registration (op->rx_reg_dev == NULL). This silently did not re-enable frame delivery for that updated filter. bcm_rx_setup() now re-registers in that case, while leaving rx_ops with ifindex = 0 (all CAN devices) which never carry a tracked rx_reg_dev registered as-is. TX: bcm_notify() only handled bo->rx_ops on NETDEV_UNREGISTER, leaving tx_ops with an active cyclic transmission re-arming its hrtimer indefinitely to execute bcm_tx_timeout_handler(). Cancelling the hrtimer prevents the runaway timer and any injection into a later reused ifindex, since nothing else calls bcm_can_tx() for the op until an explicit TX_SETUP update re-arms it. Unlike bcm_rx_unreg(), which clears the tracked rx_reg_dev for rx_ops, the ifindex is intentionally left unchanged for tx_ops. bcm_tx_setup() always rejects ifindex 0, so clearing it would strand the op: neither a later TX_SETUP (bcm_find_op()) nor TX_DELETE (bcm_delete_tx_op()) could ever find it again, since both require an exact ifindex match.