From ac0bf025d2c0e88097f0ab247e7460053fef7e9d Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Mon, 11 Dec 2017 06:35:20 -0500
Subject: [PATCH 01/24] ima: Use i_version only when filesystem supports it
Git-commit: ac0bf025d2c0e88097f0ab247e7460053fef7e9d
Patch-mainline: v4.16-rc1
References: bsc#1081186

i_version is only supported by a filesystem when the SB_I_VERSION
flag is set. This patch tests for the SB_I_VERSION flag before using
i_version. If we can't use i_version to detect a file change then we
must assume the file has changed in the last_writer path and remeasure
it.

On filesystems without i_version support IMA used to measure a file
only once and didn't detect any changes to a file. With this patch
IMA now works properly on these filesystems.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>

---
 security/integrity/ima/ima_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 2aebb7984437..0d9b9beb0dd2 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -123,7 +123,8 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint,
 
 	inode_lock(inode);
 	if (atomic_read(&inode->i_writecount) == 1) {
-		if ((iint->version != inode->i_version) ||
+		if (!IS_I_VERSION(inode) ||
+		    (iint->version != inode->i_version) ||
 		    (iint->flags & IMA_NEW_FILE)) {
 			iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
 			iint->measured_pcrs = 0;
-- 
2.10.0