[PATCH] dm: verity-loadpin: Add NULL pointer check for 'bdev' parameter

[Matthias Kaehlcke]

Add a NULL check for the 'bdev' parameter of
dm_verity_loadpin_is_bdev_trusted(). The function is called
by loadpin_check(), which passes the block device that
corresponds to the super block of the file system from which
a file is being loaded. Generally a super_block structure has
an associated block device, however that is not always the
case (e.g. tmpfs).

Cc: stable@xxxxxxxxxxxxxxx # v6.0+
Fixes: b6c1c5745ccc ("dm: Add verity helpers for LoadPin")
Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
---

 drivers/md/dm-verity-loadpin.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/md/dm-verity-loadpin.c b/drivers/md/dm-verity-loadpin.c
index 4f78cc55c251..0666699b6858 100644
--- a/drivers/md/dm-verity-loadpin.c
+++ b/drivers/md/dm-verity-loadpin.c
@@ -58,6 +58,9 @@ bool dm_verity_loadpin_is_bdev_trusted(struct block_device *bdev)
 	int srcu_idx;
 	bool trusted = false;
 
+	if (bdev == NULL)
+		return false;
+
 	if (list_empty(&dm_verity_loadpin_trusted_root_digests))
 		return false;
 
-- 
2.41.0.255.g8b1d071c50-goog