block: add pgmap check to biovec_phys_mergeable
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: block: add pgmap check to biovec_phys_mergeable biovec_phys_mergeable() is used by the request merge, DMA mapping, and integrity merge paths to decide if two physically contiguous bvec segments can be coalesced into one. It currently has no check for whether the segments belong to different dev_pagemaps. When zone device memory is registered in multiple chunks, each chunk gets its own dev_pagemap. A single bio can legitimately contain bvecs from different pgmaps -- iov_iter_extract_bvecs() breaks at pgmap boundaries but the outer loop in bio_iov_iter_get_pages() continues filling the same bio. If such bvecs are physically contiguous, biovec_phys_mergeable() will coalesce them, making it impossible to recover the correct pgmap for the merged segment via page_pgmap(). Add a zone_device_pages_have_same_pgmap() check to prevent merging bvec segments that span different pgmaps.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.2 and later | 6.6.140, 6.12.88, 6.18.30, 7.0.7, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 6.2 and later Fixed in 6.6.140, 6.12.88, 6.18.30, 7.0.7, 7.1 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.2 to before 6.6.140; 6.7 to before 6.12.88; 6.13 to before 6.18.30; 6.19 to before 7.0.7 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.2 to before 6.6.140; 6.7 to before 6.12.88; 6.13 to before 6.18.30; 6.19 to before 7.0.7 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.140, 6.12.88, 6.18.30, 7.0.7, 7.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-46115
- 2026-10-03 Alias added: GHSA-3588-2x8w-w62r
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-19 Weakness changed · CISA ADP
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 5
- https://git.kernel.org/stable/c/3d2ecbd444b01d6500671d1a582b7393943cf539
- https://git.kernel.org/stable/c/a7f3aa8c9df3905fe820ae36b67ba56b81587574
- https://git.kernel.org/stable/c/f17d521075325b8afc42d1baa1c28a5e9aca111f
- https://git.kernel.org/stable/c/f632dab4b841554cd6416058c61886d7db176581
- https://git.kernel.org/stable/c/13920e4b7b784b40cf4519ff1f0f3e513476a499
More Linux Kernel vulnerabilities
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- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-46115 · CVE Program
- CVE-2026-46115 · NVD
- FIRST EPSS
- GHSA-3588-2x8w-w62r · GitHub Advisory Database · CC BY 4.0
- CVE-2026-46115 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences