CVE-2026-80984

/// Technical description

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

net/smc: do not dereference an unset send buffer on the SMC-D teardown path

smc_close_stream_wait() calls smc_tx_prepared_sends() from inside its

sk_wait_event() condition, and sk_wait_event() evaluates that condition

once with the socket lock released. smcd_buf_detach() clears

conn->sndbuf_desc from smc_conn_kill() under lock_sock(), so a link group

terminating while a socket waits there leaves the helper dereferencing

NULL, faulting out of close(). SIOCOUTQ reads the field by hand, and

smc_close_cancel_work() drops the lock across two cancel_*_sync() calls.

Sample the pointer once in the helper, report nothing prepared while it is

unset, and bound the ioctl the same way. The receive tasklet dereferences

the field directly in smc_cdc_msg_recv_action(), not through this helper;

1/2 is what keeps it from running that late.

/// 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