Patch "ovl: free lower_mnt array in ovl_put_super" has been added to the 4.2-stable tree

Patch "ovl: free lower_mnt array in ovl_put_super" has been added to the 4.2-stable tree

[gregkh]

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

    ovl: free lower_mnt array in ovl_put_super

to the 4.2-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:
     ovl-free-lower_mnt-array-in-ovl_put_super.patch
and it can be found in the queue-4.2 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 5ffdbe8bf1e485026e1c7e4714d2841553cf0b40 Mon Sep 17 00:00:00 2001
From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Date: Mon, 24 Aug 2015 15:57:19 +0300
Subject: ovl: free lower_mnt array in ovl_put_super

From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>

commit 5ffdbe8bf1e485026e1c7e4714d2841553cf0b40 upstream.

This fixes memory leak after umount.

Kmemleak report:

unreferenced object 0xffff8800ba791010 (size 8):
  comm "mount", pid 2394, jiffies 4294996294 (age 53.920s)
  hex dump (first 8 bytes):
    20 1c 13 02 00 88 ff ff                           .......
  backtrace:
    [<ffffffff811f8cd4>] create_object+0x124/0x2c0
    [<ffffffff817a059b>] kmemleak_alloc+0x7b/0xc0
    [<ffffffff811dffe6>] __kmalloc+0x106/0x340
    [<ffffffffa0152bfc>] ovl_fill_super+0x55c/0x9b0 [overlay]
    [<ffffffff81200ac4>] mount_nodev+0x54/0xa0
    [<ffffffffa0152118>] ovl_mount+0x18/0x20 [overlay]
    [<ffffffff81201ab3>] mount_fs+0x43/0x170
    [<ffffffff81220d34>] vfs_kern_mount+0x74/0x170
    [<ffffffff812233ad>] do_mount+0x22d/0xdf0
    [<ffffffff812242cb>] SyS_mount+0x7b/0xc0
    [<ffffffff817b6bee>] entry_SYSCALL_64_fastpath+0x12/0x76
    [<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Fixes: dd662667e6d3 ("ovl: add mutli-layer infrastructure")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/overlayfs/super.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -544,6 +544,7 @@ static void ovl_put_super(struct super_b
 	mntput(ufs->upper_mnt);
 	for (i = 0; i < ufs->numlower; i++)
 		mntput(ufs->lower_mnt[i]);
+	kfree(ufs->lower_mnt);
 
 	kfree(ufs->config.lowerdir);
 	kfree(ufs->config.upperdir);


Patches currently in stable-queue which might be from khlebnikov@yandex-team.ru are

queue-4.2/ovl-free-stack-of-paths-in-ovl_fill_super.patch
queue-4.2/ovl-free-lower_mnt-array-in-ovl_put_super.patch