hv_netvsc: use kmap_local_page in netvsc_copy_to_send_buf
In the Linux kernel, the following vulnerability has been resolved: hv_netvsc: use kmap_local_page in netvsc_copy_to_send_buf netvsc_copy_to_send_buf() copies page buffer entries into the VMBus send buffer using phys_to_virt() on the entry PFN. Entries for the RNDIS header and the skb linear data come from kmalloc'd memory and are always in the kernel direct map, but entries for skb fragments reference page cache or user pages, which on 32-bit x86 with CONFIG_HIGHMEM=y can live above the LOWMEM boundary. For such a page phys_to_virt() returns an address outside the direct map and the subsequent memcpy() faults on the transmit softirq path, which is fatal. Map the pages with kmap_local_page() instead, handling two properties of the page buffer entries: - pb[i].pfn is a Hyper-V PFN at HV_HYP_PAGE_SIZE (4K) granularity, not a native PFN. Reconstruct the physical address first and derive the native page from it, so the mapping stays correct where PAGE_SIZE > HV_HYP_PAGE_SIZE (e.g. arm64 with 64K pages). - Since commit 41a6328b2c55 ("hv_netvsc: Preserve contiguous PFN grouping in the page buffer array"), an entry describes a full physically contiguous fragment and pb[i].len can exceed PAGE_SIZE, while kmap_local_page() maps a single page. Copy page by page, splitting at native page boundaries. The copy path only handles packets smaller than the send section size (6144 bytes by default); larger packets take the cp_partial path where only the RNDIS header is copied. So entries here are bounded by the section size and a copy is split at most once on 4K-page systems. On !CONFIG_HIGHMEM configs kmap_local_page() folds to page_address() and no mapping work is added.
Noroxi analysis
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We use this product, ask for help- Published
- Jun 25, 2026
- Updated
- Aug 5, 2026
- EPSS
- 0.5% · 41th percentile
- CWE
- —
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Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.5
- 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
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel3.16 and later · before 5.10.259
- linux linux kernel5.11 and later · before 5.15.210
- linux linux kernel5.16 and later · before 6.1.176
- linux linux kernel6.2 and later · before 6.6.143
- linux linux kernel6.7 and later · before 6.12.94
- linux linux kernel6.13 and later · before 6.18.36
- linux linux kernel6.19 and later · before 7.0.13
- linux linux kernel7.1
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
- 3.16affected
- c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e and later · before 16514afeb7d3d121072ba9a0b640d6c1c5507db0affected · git
- c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e and later · before a82d4251918f37d9c5aab7b365157669fb885ec3affected · git
- c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e and later · before 695c59cf7bf707e6ff8cea01916ee50e86616933affected · git
- c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e and later · before 09b8a7aa5a341bb345dc492aac139525efa13515affected · git
- c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e and later · before 918c0c988239aa5ab96b254e504d191af6191061affected · git
- c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e and later · before 0b38870d81ab3a04c1ab0598d9d3285f5d9d0584affected · git
- c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e and later · before fe7221b4346418d27ec2daccfc09df6692b76f0baffected · git
- c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e and later · before 004e9ecfe6c5384f9e0b2f6f6389d42ec22789afaffected · git
- before 3.16not 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 6.1.176-1 | 6.1.176-1 |
| Debian:13 | linux | before 6.12.94-1 | 6.12.94-1 |
| Debian:14 | linux | before 7.0.13-1 | 7.0.13-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
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 | 004e9ecfe6c5384f9e0b2f6f6389d42ec22789af | Vendor (CNA) |
| Linux Linux | 09b8a7aa5a341bb345dc492aac139525efa13515 | Vendor (CNA) |
| Linux Linux | 0b38870d81ab3a04c1ab0598d9d3285f5d9d0584 | Vendor (CNA) |
| Linux Linux | 16514afeb7d3d121072ba9a0b640d6c1c5507db0 | Vendor (CNA) |
| Linux Linux | 695c59cf7bf707e6ff8cea01916ee50e86616933 | Vendor (CNA) |
| Linux Linux | 918c0c988239aa5ab96b254e504d191af6191061 | Vendor (CNA) |
| Linux Linux | a82d4251918f37d9c5aab7b365157669fb885ec3 | Vendor (CNA) |
| Linux Linux | fe7221b4346418d27ec2daccfc09df6692b76f0b | Vendor (CNA) |
| debian:linux | 6.1.176-1 · 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
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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/004e9ecfe6c5384f9e0b2f6f6389d42ec22789af
- git.kernel.org/stable/c/09b8a7aa5a341bb345dc492aac139525efa13515
- git.kernel.org/stable/c/0b38870d81ab3a04c1ab0598d9d3285f5d9d0584
- git.kernel.org/stable/c/16514afeb7d3d121072ba9a0b640d6c1c5507db0
- git.kernel.org/stable/c/695c59cf7bf707e6ff8cea01916ee50e86616933
- git.kernel.org/stable/c/918c0c988239aa5ab96b254e504d191af6191061
- git.kernel.org/stable/c/a82d4251918f37d9c5aab7b365157669fb885ec3
- git.kernel.org/stable/c/fe7221b4346418d27ec2daccfc09df6692b76f0b
Vendor advisories and official records. Exploit/PoC links are deliberately left out.