From a2a2c3c8580a9158bca61221648fd6d5c98c443a Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Wed, 27 Sep 2017 08:39:54 +0200
Subject: [PATCH] ima: Use i_version only when filesystem supports it
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: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
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 21330d0455b0..6d78cb26784d 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -133,7 +133,8 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint,
if (atomic_read(&inode->i_writecount) == 1) {
update = test_and_clear_bit(IMA_UPDATE_XATTR,
&iint->atomic_flags);
- 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;
--
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