s390/dasd: Fix undersized format-check buffer
In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Fix undersized format-check buffer fmt_buffer_size in dasd_eckd_check_device_format() is declared as int, even though one of the multiplicands, sizeof(struct eckd_count), is a size_t. The expression trkcount * rpt_max * sizeof(struct eckd_count) is therefore correctly evaluated at 64-bit width, but the result is silently truncated when it is stored back into the 32-bit fmt_buffer_size variable. For a sufficiently large track range (start_unit/stop_unit are caller-controlled) this truncation yields a buffer size far smaller than the number of tracks actually requested. kzalloc() then succeeds with an undersized allocation, while the subsequent channel program build still operates on the untruncated track count and writes past the end of that buffer. Compute the buffer size with check_mul_overflow() and keep it in a size_t, so that a value that no longer fits results in -EINVAL instead of a silently truncated allocation size.
- Published
- Aug 28, 2026
- Updated
- Aug 29, 2026
- EPSS
- 0.2% · 6th percentile
- CWE
- —
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.8
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
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Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 4.7affected
- 8fd575200db5b53f6ea6818dd017f1b43190db12 and later · before aca18289c86f22d3fc2f3f6ff615286e7b1702f6affected · git
- 8fd575200db5b53f6ea6818dd017f1b43190db12 and later · before 9f88dda2f22927d22498801a92cab6a9424eaf86affected · git
- 8fd575200db5b53f6ea6818dd017f1b43190db12 and later · before e16e0fc54120cee3c6f0362de95aab6792865857affected · git
- 8fd575200db5b53f6ea6818dd017f1b43190db12 and later · before 87f3389cd3920714c53e704778f7ca7f1cf0c39caffected · git
- 8fd575200db5b53f6ea6818dd017f1b43190db12 and later · before 7f40b346462f563a0d6e841a77b5163d2a882a04affected · git
- before 4.7not affected · semver
- 6.6.151 and later · up to and including 6.6.*not affected · semver
- 6.12.103 and later · up to and including 6.12.*not affected · semver
- 6.18.44 and later · up to and including 6.18.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | all versions | — |
| Debian:12 | linux-6.12 | before 6.12.107-1~deb12u1 | 6.12.107-1~deb12u1 |
| Debian:13 | linux | before 6.12.105-1 | 6.12.105-1 |
| Debian:14 | linux | before 7.1.8-1 | 7.1.8-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
- CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 7f40b346462f563a0d6e841a77b5163d2a882a04 | Vendor (CNA) |
| Linux Linux | 87f3389cd3920714c53e704778f7ca7f1cf0c39c | Vendor (CNA) |
| Linux Linux | 9f88dda2f22927d22498801a92cab6a9424eaf86 | Vendor (CNA) |
| Linux Linux | aca18289c86f22d3fc2f3f6ff615286e7b1702f6 | Vendor (CNA) |
| Linux Linux | e16e0fc54120cee3c6f0362de95aab6792865857 | Vendor (CNA) |
| debian:linux | 6.12.105-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.107-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
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Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/7f40b346462f563a0d6e841a77b5163d2a882a04
- git.kernel.org/stable/c/87f3389cd3920714c53e704778f7ca7f1cf0c39c
- git.kernel.org/stable/c/9f88dda2f22927d22498801a92cab6a9424eaf86
- git.kernel.org/stable/c/aca18289c86f22d3fc2f3f6ff615286e7b1702f6
- git.kernel.org/stable/c/e16e0fc54120cee3c6f0362de95aab6792865857
Vendor advisories and official records. Exploit/PoC links are deliberately left out.