From: Sarthak Kukreti <sarthakkukreti@google.com>
Date: Tue, 31 May 2022 19:56:40 +0000 (-0400)
Subject: dm verity: set DM_TARGET_IMMUTABLE feature flag
X-Git-Tag: v5.18.2~27
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=417c73db67ea7ad8f03dfd34c6b0bb5f54294fa9;p=thirdparty%2Fkernel%2Fstable.git

dm verity: set DM_TARGET_IMMUTABLE feature flag

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@vger.kernel.org
Signed-off-by: Sarthak Kukreti <sarthakkukreti@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index 80133aae0db37..d6dbd47492a85 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -1312,6 +1312,7 @@ bad:
 
 static struct target_type verity_target = {
 	.name		= "verity",
+	.features	= DM_TARGET_IMMUTABLE,
 	.version	= {1, 8, 0},
 	.module		= THIS_MODULE,
 	.ctr		= verity_ctr,