CVEvulnerability
CVE-2022-50428
5.5 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2025-10-01
- Last modified
- 2026-06-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 ([email protected])
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-193
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.
Affected configurations
• linux linux kernel (>= 5.10 < 5.15.87)
• linux linux kernel (>= 5.16 < 6.0.18)
• linux linux kernel (>= 6.1 < 6.1.4)
Related
Weakness · CWE (1)
- CWE-193 Off-by-one Error weakness
References
- https://git.kernel.org/stable/c/18f28f13301d1afb8cea9c4ddcecdbff14488ec6 Patch
- https://git.kernel.org/stable/c/48a6a66db82b8043d298a630f22c62d43550cae5 Patch
- https://git.kernel.org/stable/c/5439ad45c0d0c8db41eb6f4dce6f778f15a5ee16 Patch
- https://git.kernel.org/stable/c/5ca65dffdead16572ca046c43fb576b227f7f635 Patch