[PATCH] nvdimm/pmem: Fix leak on dax_add_host() failure

[Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>]

Fix a leak on dax_add_host() error, where "goto out_cleanup_dax" is done
before setting pmem->dax_dev, which therefore issues the two following
calls on NULL pointers:

out_cleanup_dax:
        kill_dax(pmem->dax_dev);
        put_dax(pmem->dax_dev);

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Alasdair Kergon <agk@xxxxxxxxxx>
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-cxl@xxxxxxxxxxxxxxx
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: linux-xfs@xxxxxxxxxxxxxxx
Cc: dm-devel@xxxxxxxxxxxxxxx
Cc: nvdimm@xxxxxxxxxxxxxxx
---
 drivers/nvdimm/pmem.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 4e8fdcb3f1c8..9fe358090720 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -566,12 +566,11 @@ static int pmem_attach_disk(struct device *dev,
 	set_dax_nomc(dax_dev);
 	if (is_nvdimm_sync(nd_region))
 		set_dax_synchronous(dax_dev);
+	pmem->dax_dev = dax_dev;
 	rc = dax_add_host(dax_dev, disk);
 	if (rc)
 		goto out_cleanup_dax;
 	dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
-	pmem->dax_dev = dax_dev;
-
 	rc = device_add_disk(dev, disk, pmem_attribute_groups);
 	if (rc)
 		goto out_remove_host;
-- 
2.39.2