nvdimm/btt: Handle preemption in BTT lane acquisition
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · Low
- 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: nvdimm/btt: Handle preemption in BTT lane acquisition BTT lanes serialize access to per-lane metadata and workspace state during BTT I/O. The btt-check unit test reports data mismatches during BTT writes due to a race in lane acquisition that can lead to silent data corruption. The existing lane model uses a spinlock together with a per-CPU recursion count. That recursion model stopped being valid after BTT lanes became preemptible: another task can run on the same CPU, observe a non-zero recursion count, bypass locking, and use the same lane concurrently. BTT lanes are also held across arena_write_bytes() calls. That path reaches nsio_rw_bytes(), which flushes writes with nvdimm_flush(). Some provider flush callbacks can sleep, making a spinlock the wrong primitive for the lane lifetime. Replace the spinlock-based recursion model with a dynamically allocated per-lane mutex array and take the lane lock unconditionally. Add might_sleep() to catch any future atomic-context caller. Found with the ndctl unit test btt-check.sh.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- 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 | 6.1.63 to before 6.1.178; 6.6.2 to before 6.6.145; 4.19.299 to before 4.20; 5.4.261 to before 5.5; 5.10.201 to before 5.11; 5.15.139 to before 5.16; 6.5.12 to before 6.6 | 6.1.178, 6.6.145, 4.20, 5.5, 5.11, 5.16, 6.6 | Patch available | CNA |
| Linux | Linux | 6.7 and later | 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2 | Patch available | CNA |
- Linux VendorLinux Affected 6.1.63 to before 6.1.178; 6.6.2 to before 6.6.145; 4.19.299 to before 4.20; 5.4.261 to before 5.5; 5.10.201 to before 5.11; 5.15.139 to before 5.16; 6.5.12 to before 6.6 Fixed in 6.1.178, 6.6.145, 4.20, 5.5, 5.11, 5.16, 6.6 Patch available CNA
- Linux VendorLinux Affected 6.7 and later Fixed in 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2 Patch available CNA
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.178, 6.6.145, 4.20, 5.5, 5.11, 5.16, 6.6
- Fix · CNA Linux (Linux) Fixed in 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
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-2026-74365
- 2026-10-03 Alias added: GHSA-h26r-wqjv-57jf
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-26 CVSS score changed · Red Hat
- 2026-10-29 Affected versions changed · Red Hat
References
Other 6
- https://git.kernel.org/stable/c/fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735
- https://git.kernel.org/stable/c/73e35c1bdfa160b41fdbe204e02325f0687de506
- https://git.kernel.org/stable/c/417918783bcfe0be135019df16a267b3af442efd
- https://git.kernel.org/stable/c/5c53406098b599c420b031e6ec5ba8a2f3794c50
- https://git.kernel.org/stable/c/4eafa810b042d985ec6bbf5b514414e73cee6f6f
- https://git.kernel.org/stable/c/8d4b989d9c9afe5f185aa5853b666fc4617afe9e
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Sources
- CVE-2026-74365 · CVE Program
- CVE-2026-74365 · NVD
- FIRST EPSS
- GHSA-h26r-wqjv-57jf · GitHub Advisory Database · CC BY 4.0
- CVE-2026-74365 · 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