CVE-2022-50428
ext4: fix off-by-one errors in fast-commit block filling
- Published
- Updated
- Reserved
- Assigned by
- Linux
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.16% · top 95% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Weakness
Affected products
- affected aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e – < 18f28f13301d1afb8cea9c4ddcecdbff14488ec6
- affected aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e – < 5ca65dffdead16572ca046c43fb576b227f7f635
- affected aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e – < 5439ad45c0d0c8db41eb6f4dce6f778f15a5ee16
- affected aa75f4d3daaeb1389b9cce9d6b84401eaf228d4e – < 48a6a66db82b8043d298a630f22c62d43550cae5
- affected 5.10
- unaffected < 5.10
- unaffected 5.15.87 – ≤ 5.15.*
- unaffected 6.0.18 – ≤ 6.0.*
- unaffected 6.1.4 – ≤ 6.1.*
- unaffected 6.2 – ≤ *
References (4)
- https://git.kernel.org/stable/c/18f28f13301d1afb8cea9c4ddcecdbff14488ec6 (opens in a new tab)
- https://git.kernel.org/stable/c/5ca65dffdead16572ca046c43fb576b227f7f635 (opens in a new tab)
- https://git.kernel.org/stable/c/5439ad45c0d0c8db41eb6f4dce6f778f15a5ee16 (opens in a new tab)
- https://git.kernel.org/stable/c/48a6a66db82b8043d298a630f22c62d43550cae5 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2022-50428)Record last updated .