ext4: only use i_size_high for regular files
Directories are not allowed to be bigger than 2GB, so don't use
i_size_high for anything other than regular files. E2fsck should
complain about these inodes, but the simplest thing to do for the
kernel is to only use i_size_high for regular files.
This prevents an intentially corrupted filesystem from causing the
kernel to burn a huge amount of CPU and issuing error messages such
as:
EXT4-fs warning (device loop0): ext4_block_to_path: block 135090028 > max
Thanks to David Maciejak from Fortinet's FortiGuard Global Security
Research Team for reporting this issue.
http://bugzilla.kernel.org/show_bug.cgi?id=12375
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index a6444ce..49484ba 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -360,9 +360,9 @@
final = ptrs;
} else {
ext4_warning(inode->i_sb, "ext4_block_to_path",
- "block %lu > max",
+ "block %lu > max in inode %lu",
i_block + direct_blocks +
- indirect_blocks + double_blocks);
+ indirect_blocks + double_blocks, inode->i_ino);
}
if (boundary)
*boundary = final - 1 - (i_block & (ptrs - 1));