commit 71755ee5350b63fb1f283de8561cdb61b47f4d1d upstream.

The squashfs fragment reading code doesn't actually verify that the
fragment is inside the fragment table.  The end result _is_ verified to
be inside the image when actually reading the fragment data, but before
that is done, we may end up taking a page fault because the fragment
table itself might not even exist.

Another report from Anatoly and his endless squashfs image fuzzing.

Reported-by: Анатолий Тросиненко <anatoly.trosinenko@gmail.com>
Acked-by:: Phillip Lougher <phillip.lougher@gmail.com>,
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d512584780d3e6a7cacb2f482834849453d444a1 upstream.

Anatoly reports another squashfs fuzzing issue, where the decompression
parameters themselves are in a compressed block.

This causes squashfs_read_data() to be called in order to read the
decompression options before the decompression stream having been set
up, making squashfs go sideways.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Acked-by: Phillip Lougher <phillip.lougher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 01cfb7937a9af2abb1136c7e89fbf3fd92952956 upstream.

Anatoly Trosinenko reports that a corrupted squashfs image can cause a
kernel oops.  It turns out that squashfs can end up being confused about
negative fragment lengths.

The regular squashfs_read_data() does check for negative lengths, but
squashfs_read_metadata() did not, and the fragment size code just
blindly trusted the on-disk value.  Fix both the fragment parsing and
the metadata reading code.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that the xattr handler is passed to the xattr handler operations, we
have access to the attribute name prefix, so simplify the squashfs xattr
handlers a bit.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The xattr_handler operations are currently all passed a file system
specific flags value which the operations can use to disambiguate between
different handlers; some file systems use that to distinguish the xattr
namespace, for example.  In some oprations, it would be useful to also have
access to the handler prefix.  To allow that, pass a pointer to the handler
to operations instead of the flags value alone.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

list_entry is just a wrapper for container_of, but it is arguably
wrong (and slightly confusing) to use it when the pointed-to struct
member is not a struct list_head. Use container_of directly instead.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Add the glue code, and also update the documentation.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>

Add support for reading file systems compressed with the
LZ4 compression algorithm.

This patch adds the LZ4 decompressor wrapper code.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>

- Convert printk to pr_foo()
- Add pr_fmt for future logging entries
- Coalesce formats

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>