SELinux: Fix memory leak upon loading policy
commit 8ed8146 upstream.

Hello.

I got below leak with linux-3.10.0-54.0.1.el7.x86_64 .

[  681.903890] kmemleak: 5538 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

Below is a patch, but I don't know whether we need special handing for undoing
ebitmap_set_bit() call.

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>>From fe97527 Mon Sep 17 00:00:00 2001

From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Mon, 6 Jan 2014 16:30:21 +0900
Subject: SELinux: Fix memory leak upon loading policy

Commit 2463c26d "SELinux: put name based create rules in a hashtable" did not
check return value from hashtab_insert() in filename_trans_read(). It leaks
memory if hashtab_insert() returns error.

  unreferenced object 0xffff88005c9160d0 (size 8):

    comm "systemd", pid 1, jiffies 4294688674 (age 235.265s)

    hex dump (first 8 bytes):

      57 0b 00 00 6b 6b 6b a5                          W...kkk.

    backtrace:

      [<ffffffff816604ae>] kmemleak_alloc+0x4e/0xb0

      [<ffffffff811cba5e>] kmem_cache_alloc_trace+0x12e/0x360

      [<ffffffff812aec5d>] policydb_read+0xd1d/0xf70

      [<ffffffff812b345c>] security_load_policy+0x6c/0x500

      [<ffffffff812a623c>] sel_write_load+0xac/0x750

      [<ffffffff811eb680>] vfs_write+0xc0/0x1f0

      [<ffffffff811ec08c>] SyS_write+0x4c/0xa0

      [<ffffffff81690419>] system_call_fastpath+0x16/0x1b

      [<ffffffffffffffff>] 0xffffffffffffffff

However, we should not return EEXIST error to the caller, or the systemd will
show below message and the boot sequence freezes.

  systemd[1]: Failed to load SELinux policy. Freezing.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Anonymous <kernelhackx@gmx.com>