[LU-15601] osd_inode_iteration err ptr dereference, wrong bitmap checks in osd scrub

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.15.0
• Affects Version/s: Lustre 2.15.0
• Severity: 3
• Assignee: Andreas Dilger
• Reporter: Oleg Drokin

Description

it looks like osd_inode_iteration and all around code in osd-ldiskfs/osd_scrub.c is incorrect

osd_inode_iteration:

                param->bitmap = ldiskfs_read_inode_bitmap(param->sb, param->bg);
                if (!param->bitmap) {
                        CERROR("%s: fail to read bitmap for %u, "
                               "scrub will stop, urgent mode\n",
                               osd_scrub2name(scrub), (__u32)param->bg);
                        RETURN(-EIO);
                }
 

But the comment in ldiskfs_read_inode_bitmap() is incorrect:

 * Return buffer_head of bitmap on success or NULL.
 */
struct buffer_head *
ldiskfs_read_inode_bitmap(struct super_block *sb, ldiskfs_group_t block_group)
{
        struct ldiskfs_group_desc *desc;
        struct ldiskfs_sb_info *sbi = LDISKFS_SB(sb);
        struct buffer_head *bh = NULL;
        ldiskfs_fsblk_t bitmap_blk;
        int err;        desc = ldiskfs_get_group_desc(sb, block_group, NULL);
        if (!desc)
                return ERR_PTR(-EFSCORRUPTED);
...
                return ERR_PTR(-EIO);
 

and so on.

this is not the case in centos7, but on rhel8 is already affected