CVE-2021-46946 Information

Description

In the Linux kernel the following vulnerability has been resolved:

ext4: fix check to prevent false positive report of incorrect used inodes

Commit <50122847007> (xt4: 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.

Reference

https://git.kernel.org/stable/c/539ba4ebc467260225898e67ea53cbb73308f894 https://git.kernel.org/stable/c/d2e121be8d318524a61e13ca15b5bfab2d0b63c7 https://git.kernel.org/stable/c/e70db6e43286a17c3dfc840fcee662de183b6a81 https://git.kernel.org/stable/c/7687f5aba0f50c7ff8040e506bae184e59c8e7b8 https://git.kernel.org/stable/c/9c61387630a54e35b96a90608aafd369ffb86f39 https://git.kernel.org/stable/c/098b257563b959f4ca6c1d82fde0ee727792cb19 https://git.kernel.org/stable/c/f42789ee5f96743cdb5f69445cab3609458733f7 https://git.kernel.org/stable/c/e18d76a12b34791bc0318a0e0c0fa5863cd8dabf https://git.kernel.org/stable/c/a149d2a5cabbf6507a7832a1c4fd2593c55fd450