Patch "cred: Reject inodes with invalid ids in set_create_file_as()" has been added to the 4.7-stable tree

Patch "cred: Reject inodes with invalid ids in set_create_file_as()" has been added to the 4.7-stable tree

[gregkh]

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

    cred: Reject inodes with invalid ids in set_create_file_as()

to the 4.7-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:
     cred-reject-inodes-with-invalid-ids-in-set_create_file_as.patch
and it can be found in the queue-4.7 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 5f65e5ca286126a60f62c8421b77c2018a482b8a Mon Sep 17 00:00:00 2001
From: Seth Forshee <seth.forshee@canonical.com>
Date: Tue, 26 Apr 2016 14:36:24 -0500
Subject: cred: Reject inodes with invalid ids in set_create_file_as()

From: Seth Forshee <seth.forshee@canonical.com>

commit 5f65e5ca286126a60f62c8421b77c2018a482b8a upstream.

Using INVALID_[UG]ID for the LSM file creation context doesn't
make sense, so return an error if the inode passed to
set_create_file_as() has an invalid id.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/cred.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -689,6 +689,8 @@ EXPORT_SYMBOL(set_security_override_from
  */
 int set_create_files_as(struct cred *new, struct inode *inode)
 {
+	if (!uid_valid(inode->i_uid) || !gid_valid(inode->i_gid))
+		return -EINVAL;
 	new->fsuid = inode->i_uid;
 	new->fsgid = inode->i_gid;
 	return security_kernel_create_files_as(new, inode);


Patches currently in stable-queue which might be from seth.forshee@canonical.com are

queue-4.7/cred-reject-inodes-with-invalid-ids-in-set_create_file_as.patch
queue-4.7/fs-check-for-invalid-i_uid-in-may_follow_link.patch