CVE-2026-72124

/// Technical description

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

can: isotp: serialize TX state transitions under so->rx_lock

The TX state machine (so->tx.state) is driven from three contexts:

sendmsg() claiming and progressing a transfer, the RX path consuming

Flow Control/echo frames, and two hrtimers timing out a stalled

transfer. Mixing a lock-free cmpxchg() claim in sendmsg() with

hrtimer_cancel() calls made under so->rx_lock elsewhere left windows

where a frame or timer callback could act on a state that had already

moved on, corrupting an unrelated transfer.

so->rx_lock now covers the full lifecycle of a TX claim: sendmsg()

takes it to check so->tx.state is ISOTP_IDLE, switch it to

ISOTP_SENDING, bump so->tx_gen and drain the previous transfer's

timers - all as one critical section. isotp_rcv_fc()/isotp_rcv_cf()

already run under this lock via isotp_rcv(), and isotp_rcv_echo() now

takes it itself, so none of them can ever observe a transfer mid-claim.

This also means a tra

/// 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