Messages in this thread |  | | Subject | Re: [PATCH 4/5] selinux: Enhance selinux to always ignore private inodes. | From | Stephen Smalley <> | Date | Fri, 09 Feb 2007 07:26:17 -0500 |
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On Thu, 2007-02-08 at 16:02 -0700, Eric W. Biederman wrote: > From: Stephen Smalley <sds@tycho.nsa.gov> > > Hmmm...turns out to not be quite enough, as the /proc/sys inodes aren't > truly private to the fs, so we can run into them in a variety of > security hooks beyond just the inode hooks, such as > security_file_permission (when reading and writing them via the vfs > helpers), security_sb_mount (when mounting other filesystems on > directories in proc like binfmt_misc), and deeper within the security > module itself (as in flush_unauthorized_files upon inheritance across > execve). So I think we have to add an IS_PRIVATE() guard within > SELinux, as below. Note however that the use of the private flag here > could be confusing, as these inodes are _not_ private to the fs, are > exposed to userspace, and security modules must implement the sysctl > hook to get any access control over them.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> > > --- > security/selinux/hooks.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index de16b9f..ff9fccc 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -1077,6 +1077,9 @@ static int inode_has_perm(struct task_struct *tsk, > struct inode_security_struct *isec; > struct avc_audit_data ad; > > + if (unlikely (IS_PRIVATE (inode))) > + return 0; > + > tsec = tsk->security; > isec = inode->i_security; > -- Stephen Smalley National Security Agency
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