CVE-2026-80979

/// Technical description

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

net/smc: unregister the connection before draining the rx tasklet

smc_conn_free() calls smc_ism_unset_conn() only while the link group is

still on its device list, and never sets conn->killed.

smc_lgr_terminate_sched() unlinks the group immediately and defers killing

its connections to a work item, so a connection freed in that window keeps

its smcd->conn[] slot with both gates in smcd_handle_irq() open, and the

device can re-arm the receive tasklet after tasklet_kill() has returned. On

the DMB-nocopy path the ghost send buffer is freed right after that drain,

so the re-armed tasklet dereferences it.

Unregister unconditionally and drain before the detach at both teardown

sites, mirroring rmb_desc, which smc_buf_unuse() releases after the drain.

Clear conn->sndbuf_desc before freeing it as well, so a reader that samples

the pointer cannot get one that is already freed.

/// 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