From 0ec060d1881a24c270fdf0d6616e33e23a209ef2 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Thu, 3 Apr 2014 14:50:31 -0700 Subject: 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 Cc: Andreas Rohner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/dat.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'fs/nilfs2/dat.c') diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c index fa0f80308c2d..0d5fada91191 100644 --- a/fs/nilfs2/dat.c +++ b/fs/nilfs2/dat.c @@ -484,6 +484,18 @@ int nilfs_dat_read(struct super_block *sb, size_t entry_size, struct nilfs_dat_info *di; int err; + if (entry_size > sb->s_blocksize) { + printk(KERN_ERR + "NILFS: too large DAT entry size: %zu bytes.\n", + entry_size); + return -EINVAL; + } else if (entry_size < NILFS_MIN_DAT_ENTRY_SIZE) { + printk(KERN_ERR + "NILFS: too small DAT entry size: %zu bytes.\n", + entry_size); + return -EINVAL; + } + dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO); if (unlikely(!dat)) return -ENOMEM; -- cgit v1.2.3