nilfs2: verify metadata sizes read from disk
authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Thu, 3 Apr 2014 21:50:31 +0000 (14:50 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 3 Apr 2014 23:21:26 +0000 (16:21 -0700)
commit0ec060d1881a24c270fdf0d6616e33e23a209ef2
treea4c2d5ca63ffabde64759d2c238773d7114e34b7
parentf9f32c44e7016c61f8c60afbe461fbc7d5a6c7cc
nilfs2: verify metadata sizes read from disk

Add code to check sizes of on-disk data of metadata files such as inode
size, segment usage size, DAT entry size, and checkpoint size.  Although
these sizes are read from disk, the current implementation doesn't check
them.

If these sizes are not sane on disk, it can cause out-of-range access to
metadata or memory access overrun on metadata block buffers due to
overflow in sundry calculations.

Both lower limit and upper limit of metadata sizes are verified to
prevent these issues.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/nilfs2/cpfile.c
fs/nilfs2/dat.c
fs/nilfs2/sufile.c
fs/nilfs2/the_nilfs.c
include/linux/nilfs2_fs.h