ntfs3: validate split-point offset in indx_insert_into_buffer
In the Linux kernel, the following vulnerability has been resolved: ntfs3: validate split-point offset in indx_insert_into_buffer indx_insert_into_buffer() computes used = used1 - to_copy - sp_size; memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off)); where sp and sp_size come from hdr_find_split(). hdr_find_split() walks entries by le16_to_cpu(e->size) without validating that each step stays within hdr->used or that the size field is at least sizeof(struct NTFS_DE). index_hdr_check(), the on-load gatekeeper, only validates header-level fields (used, total, de_off) and does not walk per-entry sizes. A crafted NTFS image whose leaf INDEX_HDR reports used == total but contains one interior NTFS_DE with size = 0xFFF0 therefore passes validation, descends to indx_insert_into_buffer() through the ntfs_create() -> indx_insert_entry() path, and makes hdr_find_split() return an sp whose sp_size (0xFFF0) greatly exceeds the remaining bytes in the buffer. The u32 subtraction underflows and the memmove count becomes a near-4-GiB value, producing an out-of-bounds kernel write that corrupts adjacent allocations and panics the kernel. Reproduced on 7.0.0-rc7 with UML + KASAN via a crafted image and a single 'touch' inside the mounted directory; crash site resolves to fs/ntfs3/index.c at the memmove. Trigger requires only local mount of an attacker-supplied filesystem image (USB, loopback, or removable media auto-mount). Reject the split whenever the chosen sp plus its declared size already extends past hdr1->used. This is the minimal fix; it preserves the existing hdr_find_split() contract and relies on the same out: cleanup path as the pre-existing error returns. A prior OOB read in the very same indx_insert_into_buffer() memmove was fixed in commit b8c44949044e ("fs/ntfs3: Fix OOB read in indx_insert_into_buffer") by tightening hdr_find_e(), but that fix does not cover the split-point size field path addressed here: sp is returned by hdr_find_split(), not hdr_find_e(), and the underflow is driven by sp->size rather than hdr->used exceeding hdr->total.
Noroxi analysis
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We use this product, ask for help- Published
- Aug 15, 2026
- Updated
- Aug 23, 2026
- EPSS
- 0.7% · 53th percentile
- CWE
- —
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Report tools
Action score
39
Monitor
Low priority for now.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.7%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 9.8
- 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.
Affected 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
- 5.15affected
- 82cae269cfa953032fbb8980a7d554d60fb00b17 and later · before 8e4ba5a38c155bb3c1c11e63cd285b178cdb099eaffected · git
- 82cae269cfa953032fbb8980a7d554d60fb00b17 and later · before 4c2f648139a0a86f4486170f72e24fedd4fae74eaffected · git
- 82cae269cfa953032fbb8980a7d554d60fb00b17 and later · before b232eb5c9fe11ec2368e9b565db69c724c35fbd2affected · git
- 82cae269cfa953032fbb8980a7d554d60fb00b17 and later · before 7bf74e6baf810fe325f111996496c678fc6e244faffected · git
- 82cae269cfa953032fbb8980a7d554d60fb00b17 and later · before f3624cc069195001c88df7a291af215f2133ff2caffected · git
- 82cae269cfa953032fbb8980a7d554d60fb00b17 and later · before 1758a564b6ebe7f4a82f23c9851d1cae15549457affected · git
- 82cae269cfa953032fbb8980a7d554d60fb00b17 and later · before f1df9d771df47aa40de6d70949c28720ae1e430daffected · git
- before 5.15not affected · semver
- 5.15.217 and later · up to and including 5.15.*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 | before 6.1.187-1 | 6.1.187-1 |
| Debian:13 | linux | before 6.12.100-1 | 6.12.100-1 |
| Debian:14 | linux | before 7.1.5-1 | 7.1.5-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
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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 | 1758a564b6ebe7f4a82f23c9851d1cae15549457 | Vendor (CNA) |
| Linux Linux | 4c2f648139a0a86f4486170f72e24fedd4fae74e | Vendor (CNA) |
| Linux Linux | 7bf74e6baf810fe325f111996496c678fc6e244f | Vendor (CNA) |
| Linux Linux | 8e4ba5a38c155bb3c1c11e63cd285b178cdb099e | Vendor (CNA) |
| Linux Linux | b232eb5c9fe11ec2368e9b565db69c724c35fbd2 | Vendor (CNA) |
| Linux Linux | f1df9d771df47aa40de6d70949c28720ae1e430d | Vendor (CNA) |
| Linux Linux | f3624cc069195001c88df7a291af215f2133ff2c | Vendor (CNA) |
| debian:linux | 6.1.187-1 · 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.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- 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
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
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CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/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/1758a564b6ebe7f4a82f23c9851d1cae15549457
- git.kernel.org/stable/c/4c2f648139a0a86f4486170f72e24fedd4fae74e
- git.kernel.org/stable/c/7bf74e6baf810fe325f111996496c678fc6e244f
- git.kernel.org/stable/c/8e4ba5a38c155bb3c1c11e63cd285b178cdb099e
- git.kernel.org/stable/c/b232eb5c9fe11ec2368e9b565db69c724c35fbd2
- git.kernel.org/stable/c/f1df9d771df47aa40de6d70949c28720ae1e430d
- git.kernel.org/stable/c/f3624cc069195001c88df7a291af215f2133ff2c
Vendor advisories and official records. Exploit/PoC links are deliberately left out.