[PATCH 5.0 098/139] dm mpath: always free attached_handler_name in parse_path()

Greg Kroah-Hartman
2019-05-23T19:37:33Z

From: Martin Wilck <mwilck@suse.com>

commit 940bc471780b004a5277c1931f52af363c2fc9da upstream.

Commit b592211c33f7 ("dm mpath: fix attached_handler_name leak and
dangling hw_handler_name pointer") fixed a memory leak for the case
where setup_scsi_dh() returns failure. But setup_scsi_dh may return
success and not "use" attached_handler_name if the
retain_attached_hwhandler flag is not set on the map. As setup_scsi_sh
properly "steals" the pointer by nullifying it, freeing it
unconditionally in parse_path() is safe.

Fixes: b592211c33f7 ("dm mpath: fix attached_handler_name leak and dangling hw_handler_name pointer")
Cc: stable@vger.kernel.org
Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/md/dm-mpath.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -882,6 +882,7 @@ static struct pgpath *parse_path(struct
if (attached_handler_name || m->hw_handler_name) {
INIT_DELAYED_WORK(&p->activate_path, activate_path_work);
r = setup_scsi_dh(p->path.dev->bdev, m, &attached_handler_name, &ti->error);
+ kfree(attached_handler_name);
if (r) {
dm_put_device(ti, p->path.dev);
goto bad;
@@ -896,7 +897,6 @@ static struct pgpath *parse_path(struct

return p;
bad:
- kfree(attached_handler_name);
free_pgpath(p);
return ERR_PTR(r);
}