Commit 383795c2 authored Jul 29, 2008 by Eric Paris Committed by James Morris Jul 30, 2008

SELinux: /proc/mounts should show what it can

Given a hosed SELinux config in which a system never loads policy or
disables SELinux we currently just return -EINVAL for anyone trying to
read /proc/mounts. This is a configuration problem but we can certainly
be more graceful. This patch just ignores -EINVAL when displaying LSM
options and causes /proc/mounts display everything else it can. If
policy isn't loaded the obviously there are no options, so we aren't
really loosing any information here.

This is safe as the only other return of EINVAL comes from
security_sid_to_context_core() in the case of an invalid sid. Even if a
FS was mounted with a now invalidated context that sid should have been
remapped to unlabeled and so we won't hit the EINVAL and will work like
we should. (yes, I tested to make sure it worked like I thought)

Signed-off-by: Eric Paris <eparis@redhat.com>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>

parent 6e86841d

security/selinux/hooks.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -998,8 +998,12 @@ static int selinux_sb_show_options(struct seq_file m, struct super_block sb)
		int rc;

		rc = selinux_get_mnt_opts(sb, &opts);
		if (rc)
		if (rc) {
		/* before policy load we may get EINVAL, don't show anything */
		if (rc == -EINVAL)
		rc = 0;
		return rc;
		}

		selinux_write_opts(m, &opts);

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