• Tetsuo Handa's avatar
    SELinux: Fix memory leak upon loading policy · 8ed81460
    Tetsuo Handa authored
    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.
    ----------
    >>From fe97527a90fe95e2239dfbaa7558f0ed559c0992 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: [PATCH] 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: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
    Acked-by: default avatarEric Paris <eparis@redhat.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarPaul Moore <pmoore@redhat.com>
    8ed81460
policydb.c 70.6 KB