This is a note to let you know that I've just added the patch titled
SELinux: do not compute transition labels on mountpoint labeled filesystems
to the 2.6.36-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-do-not-compute-transition-labels-on-mountpoint-labeled-filesystems.patch
and it can be found in the queue-2.6.36 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 415103f9932d45f7927f4b17e3a9a13834cdb9a1 Mon Sep 17 00:00:00 2001
From: Eric Paris <[email protected]>
Date: Thu, 2 Dec 2010 16:13:40 -0500
Subject: SELinux: do not compute transition labels on mountpoint labeled
filesystems
From: Eric Paris <[email protected]>
commit 415103f9932d45f7927f4b17e3a9a13834cdb9a1 upstream.
selinux_inode_init_security computes transitions sids even for filesystems
that use mount point labeling. It shouldn't do that. It should just use
the mount point label always and no matter what.
This causes 2 problems. 1) it makes file creation slower than it needs to be
since we calculate the transition sid and 2) it allows files to be created
with a different label than the mount point!
# id -Z
staff_u:sysadm_r:sysadm_t:s0-s0:c0.c1023
# sesearch --type --class file --source sysadm_t --target tmp_t
Found 1 semantic te rules:
type_transition sysadm_t tmp_t : file user_tmp_t;
# mount -o loop,context="system_u:object_r:tmp_t:s0" /tmp/fs /mnt/tmp
# ls -lZ /mnt/tmp
drwx------. root root system_u:object_r:tmp_t:s0 lost+found
# touch /mnt/tmp/file1
# ls -lZ /mnt/tmp
-rw-r--r--. root root staff_u:object_r:user_tmp_t:s0 file1
drwx------. root root system_u:object_r:tmp_t:s0 lost+found
Whoops, we have a mount point labeled filesystem tmp_t with a user_tmp_t
labeled file!
Signed-off-by: Eric Paris <[email protected]>
Reviewed-by: Reviewed-by: James Morris <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
security/selinux/hooks.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2529,7 +2529,10 @@ static int selinux_inode_init_security(s
sid = tsec->sid;
newsid = tsec->create_sid;
- if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
+ if ((sbsec->flags & SE_SBINITIALIZED) &&
+ (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
+ newsid = sbsec->mntpoint_sid;
+ else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
rc = security_transition_sid(sid, dsec->sid,
inode_mode_to_security_class(inode->i_mode),
&newsid);
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.36/selinux-define-permissions-for-dcb-netlink-messages.patch
queue-2.6.36/selinux-do-not-compute-transition-labels-on-mountpoint-labeled-filesystems.patch
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