If vhost_scsi_setup_vq_cmds fails we leave the tpg->vhost_scsi pointer
set. If the device is freed and then the user unmaps the LUN, the call to
vhost_scsi_port_unlink -> vhost_scsi_hotunplug will see the that
tpg->vhost_scsi is still set and try to use it.
This has us clear the vhost_scsi pointer in the failure path. It also
has us take tv_tpg_mutex in this failure path, because tv_tpg_vhost_count
is accessed under this mutex in vhost_scsi_drop_nexus and in the future
we will want to serialize access to tpg->vhost_scsi with that mutex
instead of the vhost_scsi_mutex.
Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
---
drivers/vhost/scsi.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index b244e7c0f514..5875241e1654 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1658,7 +1658,10 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs,
for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
tpg = vs_tpg[i];
if (tpg) {
+ mutex_lock(&tpg->tv_tpg_mutex);
+ tpg->vhost_scsi = NULL;
tpg->tv_tpg_vhost_count--;
+ mutex_unlock(&tpg->tv_tpg_mutex);
target_undepend_item(&tpg->se_tpg.tpg_group.cg_item);
}
}
--
2.25.1
