commit 8e2bad543eca5c25cd02cbc63d72557934d45f13 upstream.
do_uevent returns the value written to event_done. In case it is a
positive value, new_lockspace would undo all the work, and lockspace
would not be set. __dlm_new_lockspace, however, would treat that
positive value as a success due to commit 8511a2728a ("dlm: fix use
count with multiple joins").
Down the line, device_create_lockspace would pass that NULL lockspace to
dlm_find_lockspace_local, leading to a NULL pointer dereference.
Treating such positive values as successes prevents the problem. Given
this has been broken for so long, this is unlikely to break userspace
expectations.
Fixes: 8511a2728a ("dlm: fix use count with multiple joins")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Nazar Kalashnikov <nazarkalashnikov0@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ulrich Hecht <uli@kernel.org>
58ab38d627