[PATCH 2/2] ipe: also reject policy updates with the same version

[luca.boccassi at gmail.com]

From: Luca Boccassi <bluca at debian.org>

Currently IPE accepts an update that has the same version as the policy
being updated, but it doesn't make it a no-op nor it checks that the
old and new policyes are the same. So it is possible to change the
content of a policy, without changing its version. This is very
confusing from userspace when managing policies.
Instead change the update logic to reject updates that have the same
version with ESTALE, as that is much clearer and intuitive behaviour.

Signed-off-by: Luca Boccassi <bluca at debian.org>
---
 security/ipe/policy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/ipe/policy.c b/security/ipe/policy.c
index 5de64441dfe7..01da3a377e7f 100644
--- a/security/ipe/policy.c
+++ b/security/ipe/policy.c
@@ -115,7 +115,7 @@ int ipe_update_policy(struct inode *root, const char *text, size_t textlen,
 		goto err;
 	}
 
-	if (ver_to_u64(old) > ver_to_u64(new)) {
+	if (ver_to_u64(old) >= ver_to_u64(new)) {
 		rc = -ESTALE;
 		goto err;
 	}
-- 
2.39.5