> On Jun 17, 2018, at 9:22 PM, Theodore Ts'o <tytso@xxxxxxx> wrote:
>
> The kernel's ext4 mount-time checks were more permissive than
> e2fsprogs's libext2fs checks when opening a file system. The
> superblock is considered too insane for debugfs or e2fsck to operate
> on it, the kernel has no business trying to mount it.
>
> This will make file system fuzzing tools work harder, but the failure
> cases that they find will be more useful and be easier to evaluate.
>
> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
I thought the last hunk would conflict with Jan's patch series, but that
is for e2fsck and this is for ext4...
Reviewed-by: Andreas Dilger <adilger@xxxxxxxxx>
> ---
> fs/ext4/super.c | 37 ++++++++++++++++++++++++++-----------
> 1 file changed, 26 insertions(+), 11 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 1f955c128e0d..b37b00befd65 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -3793,6 +3793,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> le32_to_cpu(es->s_log_block_size));
> goto failed_mount;
> }
> + if (le32_to_cpu(es->s_log_cluster_size) >
> + (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
> + ext4_msg(sb, KERN_ERR,
> + "Invalid log cluster size: %u",
> + le32_to_cpu(es->s_log_cluster_size));
> + goto failed_mount;
> + }
>
> if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
> ext4_msg(sb, KERN_ERR,
> @@ -3939,13 +3946,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> "block size (%d)", clustersize, blocksize);
> goto failed_mount;
> }
> - if (le32_to_cpu(es->s_log_cluster_size) >
> - (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
> - ext4_msg(sb, KERN_ERR,
> - "Invalid log cluster size: %u",
> - le32_to_cpu(es->s_log_cluster_size));
> - goto failed_mount;
> - }
> sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
> le32_to_cpu(es->s_log_block_size);
> sbi->s_clusters_per_group =
> @@ -3966,10 +3966,10 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> }
> } else {
> if (clustersize != blocksize) {
> - ext4_warning(sb, "fragment/cluster size (%d) != "
> - "block size (%d)", clustersize,
> - blocksize);
> - clustersize = blocksize;
> + ext4_msg(sb, KERN_ERR,
> + "fragment/cluster size (%d) != "
> + "block size (%d)", clustersize, blocksize);
> + goto failed_mount;
> }
> if (sbi->s_blocks_per_group > blocksize * 8) {
> ext4_msg(sb, KERN_ERR,
> @@ -4023,6 +4023,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> ext4_blocks_count(es));
> goto failed_mount;
> }
> + if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
> + (sbi->s_cluster_ratio == 1)) {
> + ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
> + "block is 0 with a 1k block and cluster size");
> + goto failed_mount;
> + }
> +
> blocks_count = (ext4_blocks_count(es) -
> le32_to_cpu(es->s_first_data_block) +
> EXT4_BLOCKS_PER_GROUP(sb) - 1);
> @@ -4058,6 +4065,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> ret = -ENOMEM;
> goto failed_mount;
> }
> + if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
> + le32_to_cpu(es->s_inodes_count)) {
> + ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
> + le32_to_cpu(es->s_inodes_count),
> + ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
> + ret = -EINVAL;
> + goto failed_mount;
> + }
Cheers, Andreas
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