Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Cleanups and bugfixes for ext4, including some fixes to make ext4 more
  robust against maliciously crafted file system images.

  (I still don't recommend that container folks hold any delusions that
  mounting arbitary images that can be crafted by malicious attackers
  should be considered sane thing to do, though!)"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (29 commits)
  ext4: force revalidation of directory pointer after seekdir(2)
  ext4: add extra checks to ext4_xattr_block_get()
  ext4: add bounds checking to ext4_xattr_find_entry()
  ext4: move call to ext4_error() into ext4_xattr_check_block()
  ext4: don't show data=<mode> option if defaulted
  ext4: omit init_itable=n in procfs when disabled
  ext4: show more binary mount options in procfs
  ext4: simplify kobject usage
  ext4: remove unused parameters in sysfs code
  ext4: null out kobject* during sysfs cleanup
  ext4: don't allow r/w mounts if metadata blocks overlap the superblock
  ext4: always initialize the crc32c checksum driver
  ext4: fail ext4_iget for root directory if unallocated
  ext4: limit xattr size to INT_MAX
  ext4: add validity checks for bitmap block numbers
  ext4: fix comments in ext4_swap_extents()
  ext4: use generic_writepages instead of __writepage/write_cache_pages
  ext4: don't complain about incorrect features when probing
  ext4: remove EXT4_STATE_DIOREAD_LOCK flag
  ext4: fix offset overflow on 32-bit archs in ext4_iomap_begin()
  ...

1 files changed, 10 insertions, 44 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 7830d28df331..df92e3ec9913 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -66,44 +66,6 @@ void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
 		memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
 }
 
-/* Initializes an uninitialized inode bitmap */
-static int ext4_init_inode_bitmap(struct super_block *sb,
-				       struct buffer_head *bh,
-				       ext4_group_t block_group,
-				       struct ext4_group_desc *gdp)
-{
-	struct ext4_group_info *grp;
-	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	J_ASSERT_BH(bh, buffer_locked(bh));
-
-	/* If checksum is bad mark all blocks and inodes use to prevent
-	 * allocation, essentially implementing a per-group read-only flag. */
-	if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
-		grp = ext4_get_group_info(sb, block_group);
-		if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
-			percpu_counter_sub(&sbi->s_freeclusters_counter,
-					   grp->bb_free);
-		set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
-		if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
-			int count;
-			count = ext4_free_inodes_count(sb, gdp);
-			percpu_counter_sub(&sbi->s_freeinodes_counter,
-					   count);
-		}
-		set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
-		return -EFSBADCRC;
-	}
-
-	memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
-	ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
-			bh->b_data);
-	ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
-				   EXT4_INODES_PER_GROUP(sb) / 8);
-	ext4_group_desc_csum_set(sb, block_group, gdp);
-
-	return 0;
-}
-
 void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
 {
 	if (uptodate) {
@@ -160,6 +122,7 @@ static struct buffer_head *
 ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 {
 	struct ext4_group_desc *desc;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct buffer_head *bh = NULL;
 	ext4_fsblk_t bitmap_blk;
 	int err;
@@ -169,6 +132,12 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 		return ERR_PTR(-EFSCORRUPTED);
 
 	bitmap_blk = ext4_inode_bitmap(sb, desc);
+	if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
+	    (bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
+		ext4_error(sb, "Invalid inode bitmap blk %llu in "
+			   "block_group %u", bitmap_blk, block_group);
+		return ERR_PTR(-EFSCORRUPTED);
+	}
 	bh = sb_getblk(sb, bitmap_blk);
 	if (unlikely(!bh)) {
 		ext4_error(sb, "Cannot read inode bitmap - "
@@ -187,17 +156,14 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 
 	ext4_lock_group(sb, block_group);
 	if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
-		err = ext4_init_inode_bitmap(sb, bh, block_group, desc);
+		memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
+		ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
+				     sb->s_blocksize * 8, bh->b_data);
 		set_bitmap_uptodate(bh);
 		set_buffer_uptodate(bh);
 		set_buffer_verified(bh);
 		ext4_unlock_group(sb, block_group);
 		unlock_buffer(bh);
-		if (err) {
-			ext4_error(sb, "Failed to init inode bitmap for group "
-				   "%u: %d", block_group, err);
-			goto out;
-		}
 		return bh;
 	}
 	ext4_unlock_group(sb, block_group);