CVE-2022-50428

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix off-by-one errors in fast-commit block filling

Due to several different off-by-one errors, or perhaps due to a late

change in design that wasn't fully reflected in the code that was

actually merged, there are several very strange constraints on how

fast-commit blocks are filled with tlv entries:

- tlvs must start at least 10 bytes before the end of the block, even

though the minimum tlv length is 8. Otherwise, the replay code will

ignore them. (BUG: ext4_fc_reserve_space() could violate this

requirement if called with a len of blocksize - 9 or blocksize - 8.

Fortunately, this doesn't seem to happen currently.)

- tlvs must end at least 1 byte before the end of the block. Otherwise

the replay code will consider them to be invalid. This quirk

contributed to a bug (fixed by an earlier commit) where uninitialized

memory was being leaked to disk in the last byte of blocks.

Also, strangely the

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References