Patch "btrfs: fix possible leak in btrfs_ioctl_balance()" has been added to the 4.2-stable tree

Patch "btrfs: fix possible leak in btrfs_ioctl_balance()" 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

    btrfs: fix possible leak in btrfs_ioctl_balance()

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:
     btrfs-fix-possible-leak-in-btrfs_ioctl_balance.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 0f89abf56abbd0e1c6e3cef9813e6d9f05383c1e Mon Sep 17 00:00:00 2001
From: Christian Engelmayer <cengelma@gmx.at>
Date: Wed, 21 Oct 2015 00:50:06 +0200
Subject: btrfs: fix possible leak in btrfs_ioctl_balance()

From: Christian Engelmayer <cengelma@gmx.at>

commit 0f89abf56abbd0e1c6e3cef9813e6d9f05383c1e upstream.

Commit 8eb934591f8b ("btrfs: check unsupported filters in balance
arguments") adds a jump to exit label out_bargs in case the argument
check fails. At this point in addition to the bargs memory, the
memory for struct btrfs_balance_control has already been allocated.
Ownership of bctl is passed to btrfs_balance() in the good case,
thus the memory is not freed due to the introduced jump. Make sure
that the memory gets freed in any case as necessary. Detected by
Coverity CID 1328378.

Signed-off-by: Christian Engelmayer <cengelma@gmx.at>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/btrfs/ioctl.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4649,7 +4649,7 @@ locked:
 
 	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
 		ret = -EINVAL;
-		goto out_bargs;
+		goto out_bctl;
 	}
 
 do_balance:
@@ -4663,12 +4663,15 @@ do_balance:
 	need_unlock = false;
 
 	ret = btrfs_balance(bctl, bargs);
+	bctl = NULL;
 
 	if (arg) {
 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
 			ret = -EFAULT;
 	}
 
+out_bctl:
+	kfree(bctl);
 out_bargs:
 	kfree(bargs);
 out_unlock:


Patches currently in stable-queue which might be from cengelma@gmx.at are

queue-4.2/btrfs-fix-possible-leak-in-btrfs_ioctl_balance.patch