[patch 36/36] ext4: Initialize the new group descriptor when resizing the filesystem
From: Greg KH <gregkh@suse.de>
Date: 2009-02-18 22:44:59
Also in:
lkml
2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: "Theodore Ts'o" <tytso@mit.edu> (cherry picked from commit fdff73f094e7220602cc3f8959c7230517976412) Make sure all of the fields of the group descriptor are properly initialized. Previously, we allowed bg_flags field to be contain random garbage, which could trigger non-deterministic behavior, including a kernel OOPS. http://bugzilla.kernel.org/show_bug.cgi?id=12433 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- fs/ext4/resize.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c@@ -860,11 +860,13 @@ int ext4_group_add(struct super_block *s gdp = (struct ext4_group_desc *)((char *)primary->b_data + gdb_off * EXT4_DESC_SIZE(sb)); + memset(gdp, 0, EXT4_DESC_SIZE(sb)); ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */ ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */ ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */ gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count); gdp->bg_free_inodes_count = cpu_to_le16(EXT4_INODES_PER_GROUP(sb)); + gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED); gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp); /*