When we fail to expand inode from inline format to a normal format, we
restore inode to contain the original inline formatting but we forgot to
set i_lenAlloc back. The mismatch between i_lenAlloc and i_size was then
causing further problems such as warnings and lost data down the line.

Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
CC: stable@vger.kernel.org
Fixes: 7e49b6f2480c ("udf: Convert UDF to new truncate calling sequence")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

udf_expand_file_adinicb() calls directly ->writepage to write data
expanded into a page. This however misses to setup inode for writeback
properly and so we can crash on inode->i_wb dereference when submitting
page for IO like:

  BUG: kernel NULL pointer dereference, address: 0000000000000158
  #PF: supervisor read access in kernel mode
...
  <TASK>
  __folio_start_writeback+0x2ac/0x350
  __block_write_full_page+0x37d/0x490
  udf_expand_file_adinicb+0x255/0x400 [udf]
  udf_file_write_iter+0xbe/0x1b0 [udf]
  new_sync_write+0x125/0x1c0
  vfs_write+0x28e/0x400

Fix the problem by marking the page dirty and going through the standard
writeback path to write the page. Strictly speaking we would not even
have to write the page but we want to catch e.g. ENOSPC errors early.

Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
CC: stable@vger.kernel.org
Fixes: 52ebea749aae ("writeback: make backing_dev_info host cgroup-specific bdi_writebacks")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>

When memory allocation of iinfo or block allocation fails, already
allocated struct udf_inode_info gets freed with iput() and
udf_evict_inode() may look at inode fields which are not properly
initialized. Fix it by marking inode bad before dropping reference to it
in udf_new_inode().

Reported-by: syzbot+9ca499bb57a2b9e4c652@syzkaller.appspotmail.com
Signed-off-by: Jan Kara <jack@suse.cz>

udf_readdir() didn't validate the directory position it should start
reading from. Thus when user uses lseek(2) on directory file descriptor
it can trick udf_readdir() into reading from a position in the middle of
directory entry which then upsets directory parsing code resulting in
errors or even possible kernel crashes. Similarly when the directory is
modified between two readdir calls, the directory position need not be
valid anymore.

Add code to validate current offset in the directory. This is actually
rather expensive for UDF as we need to read from the beginning of the
directory and parse all directory entries. This is because in UDF a
directory is just a stream of data containing directory entries and
since file names are fully under user's control we cannot depend on
detecting magic numbers and checksums in the header of directory entry
as a malicious attacker could fake them. We skip this step if we detect
that nothing changed since the last readdir call.

Reported-by: Nathan Wilson <nate@chickenbrittle.com>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

Use the sb_bdev_nr_blocks helper instead of open coding it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20211018101130.1838532-31-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When parsing the ExtendedAttr data, malicous or corrupt attribute length
could cause kernel hangs and buffer overruns in some special cases.

Link: https://lore.kernel.org/r/20210822093332.25234-1-stian.skjelstad@gmail.com
Signed-off-by: Stian Skjelstad <stian.skjelstad@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

Currently iocharset=utf8 mount option is broken. To use UTF-8 as iocharset,
it is required to use utf8 mount option.

Fix iocharset=utf8 mount option to use be equivalent to the utf8 mount
option.

If UTF-8 as iocharset is used then s_nls_map is set to NULL. So simplify
code around, remove UDF_FLAG_NLS_MAP and UDF_FLAG_UTF8 flags as to
distinguish between UTF-8 and non-UTF-8 it is needed just to check if
s_nls_map set to NULL or not.

Link: https://lore.kernel.org/r/20210808162453.1653-4-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>

Get rid of 0-length arrays in struct fileIdentDesc. This requires a bit
of cleaning up as the second variable length array in this structure is
often used and the code abuses the fact that the first two arrays have
the same type and offset in struct fileIdentDesc.

Signed-off-by: Jan Kara <jack@suse.cz>

Declare variable length arrays using [] instead of the old-style
declarations using arrays with 0 members. Also comment out entries in
structures beyond the first variable length array (we still do keep them
in comments as a reminder there are further entries in the structure
behind the variable length array). Accessing such entries needs a
careful offset math anyway so it is safer to not have them declared.

Signed-off-by: Jan Kara <jack@suse.cz>

Remove declaration of struct virtualAllocationTable15. It is unused.

Signed-off-by: Jan Kara <jack@suse.cz>