[PATCH v2 6/7] dm-verity: correctly handle dm_bufio_client_create() failure

[Eric Biggers <ebiggers@kernel.org>]

If either of the calls to dm_bufio_client_create() in verity_fec_ctr()
fails, then dm_bufio_client_destroy() is later called with an ERR_PTR()
argument.  That causes a crash.  Fix this.

Fixes: a739ff3f543a ("dm verity: add support for forward error correction")
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 drivers/md/dm-verity-fec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c
index ef9970b889aa..7583607a8aa6 100644
--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -499,13 +499,13 @@ void verity_fec_dtr(struct dm_verity *v)
 	mempool_exit(&f->rs_pool);
 	mempool_exit(&f->prealloc_pool);
 	mempool_exit(&f->output_pool);
 	kmem_cache_destroy(f->cache);
 
-	if (f->data_bufio)
+	if (!IS_ERR_OR_NULL(f->data_bufio))
 		dm_bufio_client_destroy(f->data_bufio);
-	if (f->bufio)
+	if (!IS_ERR_OR_NULL(f->bufio))
 		dm_bufio_client_destroy(f->bufio);
 
 	if (f->dev)
 		dm_put_device(v->ti, f->dev);
 out:
-- 
2.52.0