In ext4fs_read_file in ext4fs.c, a memset can overwrite the bounds of
the destination memory region. This patch adds a check to disallow
this.

Signed-off-by: Paul Emge <paulemge@forallsecure.com>

This patch checks for 0 in several ext4 headers and gracefully
fails instead of raising a divide-by-0 exception.

Signed-off-by: Paul Emge <paulemge@forallsecure.com>

in ext4fs_read_file, it is possible for a broken/malicious file
system to cause a memcpy of a negative number of bytes, which
overflows all memory. This patch fixes the issue by checking for
a negative length.

Signed-off-by: Paul Emge <paulemge@forallsecure.com>

ext_cache_read doesn't null cache->buf, after freeing, which results
in a later function double-freeing it. This patch fixes
ext_cache_read to call ext_cache_fini instead of free.

Signed-off-by: Paul Emge <paulemge@forallsecure.com>

JOURNAL is optional for EXT4 (and EXT3) filesystems, so add support for
skipping it. This fixes corrupting EXT4 volumes without JOURNAL after
using uboot's 'ext4write' command.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>

The block count entry in the EXT4 filesystem disk structures uses
standard 512-bytes units for most of the typical files. The only
exception are HUGE files, which use the filesystem block size, but those
are not supported by uboot's EXT4 implementation anyway. This patch fixes
the EXT4 code to use proper unit count for inode block count. This fixes
errors reported by fsck.ext4 on disks with non-standard (i.e. 4KiB, in
case of new flash drives) PHYSICAL block size after using 'ext4write'
uboot's command.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>

Ext4 allows for arbitrarily sized block group descriptors when 64-bit
addressing is enabled, which was previously not properly supported. This
patch dynamically allocates a chunk of memory of the correct size.

Signed-off-by: Benjamin Lim <jarsp.ctf@gmail.com>

Hi,

when I try to load a sparse file via ext4load, I am getting the error message
'invalid extent'

After a deeper look in the code, it seems to be an issue in the function ext4fs_get_extent_block in fs/ext4/ext4_common.c:

The file starts with 1k of zeros. The blocksize is 1024. So the first extend block contains the following information:

eh_entries: 1
eh_depth: 1
ei_block 1

When the upper layer (ext4fs_read_file) asks for fileblock 0, we are running in the 'invalid extent' error message.
For me it seems, that the code is not prepared for handling a sparse block at the beginning of the file. The following change, solved my problem:

I am really not an expert in ext4 filesystems. Can somebody please have a look at this issue and give me a feedback, if I am totally wrong or not?

Re-use the functions used to write/create a file, to support creation of a
symbolic link.
The difference with a regular file are small:
- The inode mode is flagged with S_IFLNK instead of S_IFREG
- The ext2_dirent's filetype is FILETYPE_SYMLINK instead of FILETYPE_REG
- Instead of storing the content of a file in allocated blocks, the path
to the target is stored. And if the target's path is short enough, no block
is allocated and the target's path is stored in ext2_inode.b.symlink

As with regulars files, if a file/symlink with the same name exits, it is
unlinked first and then re-created.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
[trini: Fix ext4 env code]
Signed-off-by: Tom Rini <trini@konsulko.com>

There is no need to modify the buffer passed to ext4fs_write_file().
The memset() call is not required here and was likely copied from the
equivalent part of the ext4fs_read_file() function where we do need it.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>