CVE-2022-50428 ext4: fix off-by-one errors in fast-commit block filling

What is CVE-2022-50428?

CVE-2022-50428 is a medium-severity vulnerability in Linux kernel, published on 1 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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 these constraints don't apply to the replay code in e2fsprogs, which will accept any tlvs in the blocks (with no bounds checks at all, but that is a separate issue...).

Given that this all seems to be a bug, let's fix it by just filling blocks with tlv entries in the natural way.

Note that old kernels will be unable to replay fast-commit journals created by kernels that have this commit.

Weakness: CWE-193

Which versions are affected by CVE-2022-50428?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-50428?

Apply the vendor's patch.

Is CVE-2022-50428 being exploited?

There is no known exploitation of CVE-2022-50428 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2022-50428, GHSA-362x-q9rc-h58c, ROOT-OS-DEBIAN-11-CVE-2022-50428, UBUNTU-CVE-2022-50428.