Commit 1ac202e9 authored Feb 24, 2017 by Daniel Glöckner Committed by Mimi Zohar Mar 07, 2017

ima: accept previously set IMA_NEW_FILE



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>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

parent bad4417b

security/integrity/ima/ima_appraise.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -207,10 +207,11 @@ int ima_appraise_measurement(enum ima_hooks func,

		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;
		}