Vulnerability Details : CVE-2021-46946

In the Linux kernel, the following vulnerability has been resolved: ext4: fix check to prevent false positive report of incorrect used inodes Commit <50122847007> ("ext4: fix check to prevent initializing reserved inodes") check the block group zero and prevent initializing reserved inodes. But in some special cases, the reserved inode may not all belong to the group zero, it may exist into the second group if we format filesystem below. mkfs.ext4 -b 4096 -g 8192 -N 1024 -I 4096 /dev/sda So, it will end up triggering a false positive report of a corrupted file system. This patch fix it by avoid check reserved inodes if no free inode blocks will be zeroed.