From 08e589a97d3884820ccbb96fe58af36ae544e31e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Gl=C3=B6ckner?= <dg@emlix.com>
Date: Fri, 24 Feb 2017 15:05:14 +0100
Subject: [PATCH] ima: accept previously set IMA_NEW_FILE
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commit 1ac202e978e18f045006d75bd549612620c6ec3a upstream.
Modifying the attributes of a file makes ima_inode_post_setattr reset
the IMA cache flags. So if the file, which has just been created,
is opened a second time before the first file descriptor is closed,
verification fails since the security.ima xattr has not been written
yet. We therefore have to look at the IMA_NEW_FILE even if the file
already existed.
With this patch there should no longer be an error when cat tries to
open testfile:
$ rm -f testfile
$ ( echo test >&3 ; touch testfile ; cat testfile ) 3>testfile
A file being new is no reason to accept that it is missing a digital
signature demanded by the policy.
Signed-off-by: Daniel Glöckner <dg@emlix.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
security/integrity/ima/ima_appraise.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index ed5a9c110b3a..9ce9d5003dcc 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -203,10 +203,11 @@ int ima_appraise_measurement(int func, struct integrity_iint_cache *iint,
cause = "missing-hash";
status = INTEGRITY_NOLABEL;
- if (opened & FILE_CREATED) {
+ if (opened & FILE_CREATED)
iint->flags |= IMA_NEW_FILE;
+ if ((iint->flags & IMA_NEW_FILE) &&
+ !(iint->flags & IMA_DIGSIG_REQUIRED))
status = INTEGRITY_PASS;
- }
goto out;
}