In the Linux kernel, the following vulnerability has been resolved:
s390/qeth: fix deadlock during failing recovery
Commit 0b9902c1fcc5 ("s390/qeth: fix deadlock during recovery") removed taking disciplinemutex inside qethdoreset(), fixing potential deadlocks. An error path was missed though, that still takes disciplinemutex and thus has the original deadlock potential.
Intermittent deadlocks were seen when a qeth channel path is configured offline, causing a race between qethdoreset and ccwgroupremove. Call qethsetoffline() directly in the qethdoreset() error case and then a new variant of ccwgroupsetoffline(), without taking disciplinemutex.