From fdff73f094e7220602cc3f8959c7230517976412 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 26 Jan 2009 19:06:41 -0500 Subject: [PATCH] ext4: Initialize the new group descriptor when resizing the filesystem 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" Cc: stable@kernel.org --- fs/ext4/resize.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index c328be5d6885..c06886abd658 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -861,12 +861,13 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) 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 */ ext4_free_blks_set(sb, gdp, input->free_blocks_count); ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); - gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED); + gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED); gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp); /* -- 2.39.5