From 90547d5db50bcb2705709e420e0af51535109113 Mon Sep 17 00:00:00 2001 From: John Keeping Date: Wed, 12 May 2021 12:14:21 +0100 Subject: [PATCH] dm verity: fix require_signatures module_param permissions [ Upstream commit 0c1f3193b1cdd21e7182f97dc9bca7d284d18a15 ] The third parameter of module_param() is permissions for the sysfs node but it looks like it is being used as the initial value of the parameter here. In fact, false here equates to omitting the file from sysfs and does not affect the value of require_signatures. Making the parameter writable is not simple because going from false->true is fine but it should not be possible to remove the requirement to verify a signature. But it can be useful to inspect the value of this parameter from userspace, so change the permissions to make a read-only file in sysfs. Signed-off-by: John Keeping Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin --- drivers/md/dm-verity-verify-sig.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/dm-verity-verify-sig.c b/drivers/md/dm-verity-verify-sig.c index 614e43d..919154a 100644 --- a/drivers/md/dm-verity-verify-sig.c +++ b/drivers/md/dm-verity-verify-sig.c @@ -15,7 +15,7 @@ #define DM_VERITY_VERIFY_ERR(s) DM_VERITY_ROOT_HASH_VERIFICATION " " s static bool require_signatures; -module_param(require_signatures, bool, false); +module_param(require_signatures, bool, 0444); MODULE_PARM_DESC(require_signatures, "Verify the roothash of dm-verity hash tree"); -- 2.7.4