From: Jesper Juhl <jj@chaosbits.net>
Date: Sat, 25 Dec 2010 21:22:30 +0000 (+0000)
Subject: btrfs: Don't pass NULL ptr to func that may deref it.
X-Git-Tag: v2.6.38-rc1~14^2~5
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ff175d57f057f77d2d3031d674c2af9167a4af02;p=pandora-kernel.git

btrfs: Don't pass NULL ptr to func that may deref it.

Hi,

In fs/btrfs/inode.c::fixup_tree_root_location() we have this code:

...
 		if (!path) {
 			err = -ENOMEM;
 			goto out;
 		}
...
 	out:
 		btrfs_free_path(path);
 		return err;

btrfs_free_path() passes its argument on to other functions and some of
them end up dereferencing the pointer.
In the code above that pointer is clearly NULL, so btrfs_free_path() will
eventually cause a NULL dereference.

There are many ways to cut this cake (fix the bug). The one I chose was to
make btrfs_free_path() deal gracefully with NULL pointers. If you
disagree, feel free to come up with an alternative patch.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---

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