[PATCH 4.14 19/23] dm verity: set DM_TARGET_IMMUTABLE feature flag

[Greg Kroah-Hartman]

From: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxx>

commit 4caae58406f8ceb741603eee460d79bacca9b1b5 upstream.

The device-mapper framework provides a mechanism to mark targets as
immutable (and hence fail table reloads that try to change the target
type). Add the DM_TARGET_IMMUTABLE flag to the dm-verity target's
feature flags to prevent switching the verity target with a different
target type.

Fixes: a4ffc152198e ("dm: add verity target")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/md/dm-verity-target.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -1163,6 +1163,7 @@ bad:
 
 static struct target_type verity_target = {
 	.name		= "verity",
+	.features	= DM_TARGET_IMMUTABLE,
 	.version	= {1, 3, 0},
 	.module		= THIS_MODULE,
 	.ctr		= verity_ctr,