Patch "selinux: don't waste ebitmap space when importing NetLabel categories" has been added to the 4.1-stable tree

Patch "selinux: don't waste ebitmap space when importing NetLabel categories" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    selinux: don't waste ebitmap space when importing NetLabel categories

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     selinux-don-t-waste-ebitmap-space-when-importing-netlabel-categories.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 3324603524925c7727207027d1c15e597412d15e Mon Sep 17 00:00:00 2001
From: Paul Moore <pmoore@redhat.com>
Date: Thu, 9 Jul 2015 14:20:36 -0400
Subject: selinux: don't waste ebitmap space when importing NetLabel categories

From: Paul Moore <pmoore@redhat.com>

commit 3324603524925c7727207027d1c15e597412d15e upstream.

At present we don't create efficient ebitmaps when importing NetLabel
category bitmaps.  This can present a problem when comparing ebitmaps
since ebitmap_cmp() is very strict about these things and considers
these wasteful ebitmaps not equal when compared to their more
efficient counterparts, even if their values are the same.  This isn't
likely to cause problems on 64-bit systems due to a bit of luck on
how NetLabel/CIPSO works and the default ebitmap size, but it can be
a problem on 32-bit systems.

This patch fixes this problem by being a bit more intelligent when
importing NetLabel category bitmaps by skipping over empty sections
which should result in a nice, efficient ebitmap.

Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 security/selinux/ss/ebitmap.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/security/selinux/ss/ebitmap.c
+++ b/security/selinux/ss/ebitmap.c
@@ -153,6 +153,12 @@ int ebitmap_netlbl_import(struct ebitmap
 		if (offset == (u32)-1)
 			return 0;
 
+		/* don't waste ebitmap space if the netlabel bitmap is empty */
+		if (bitmap == 0) {
+			offset += EBITMAP_UNIT_SIZE;
+			continue;
+		}
+
 		if (e_iter == NULL ||
 		    offset >= e_iter->startbit + EBITMAP_SIZE) {
 			e_prev = e_iter;


Patches currently in stable-queue which might be from pmoore@redhat.com are

queue-4.1/selinux-don-t-waste-ebitmap-space-when-importing-netlabel-categories.patch
queue-4.1/selinux-fix-mprotect-prot_exec-regression-caused-by-mm-change.patch