{"id":"CVE-2026-74365","title":"nvdimm/btt: Handle preemption in BTT lane acquisition","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvdimm/btt: Handle preemption in BTT lane acquisition\n\nBTT lanes serialize access to per-lane metadata and workspace state\nduring BTT I/O. The btt-check unit test repor…","severity":"high","cvss":7.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= f23859748e3d530217b197e146a9ac84faf0a282 < fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735","Linux >= 6f50b414f1a0d790f11a6438a3ad6d0577eb2c18 < 73e35c1bdfa160b41fdbe204e02325f0687de506","Linux >= 36c75ce3bd299878fd9b238e9803d3817ddafbf3 < 417918783bcfe0be135019df16a267b3af442efd","Linux >= 36c75ce3bd299878fd9b238e9803d3817ddafbf3 < 5c53406098b599c420b031e6ec5ba8a2f3794c50","Linux >= 36c75ce3bd299878fd9b238e9803d3817ddafbf3 < 4eafa810b042d985ec6bbf5b514414e73cee6f6f","Linux >= 36c75ce3bd299878fd9b238e9803d3817ddafbf3 < 8d4b989d9c9afe5f185aa5853b666fc4617afe9e","Linux 2577fece583c7c05cda7ad50dde7638c962665e1","Linux 40ba3fa21250e361bdd8f00800b3e2cb6160de95","Linux b0e7a935739f33ed2bd6868b89f97dd4c2683c26","Linux 66eb7b7f23dd9aec5356e7054dd3596ae7648ff5","Linux b27751fb1f271bbb78d5993c0b10011628e40e18","Linux >= 6.1.63 < 6.1.178","Linux >= 6.6.2 < 6.6.145","Linux >= 4.19.299 < 4.20","Linux >= 5.4.261 < 5.5","Linux >= 5.10.201 < 5.11","Linux >= 5.15.139 < 5.16","Linux >= 6.5.12 < 6.6","Linux 6.7"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:54:37.742896Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:55:35.765Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74365","references":[{"url":"https://git.kernel.org/stable/c/fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735"},{"url":"https://git.kernel.org/stable/c/73e35c1bdfa160b41fdbe204e02325f0687de506"},{"url":"https://git.kernel.org/stable/c/417918783bcfe0be135019df16a267b3af442efd"},{"url":"https://git.kernel.org/stable/c/5c53406098b599c420b031e6ec5ba8a2f3794c50"},{"url":"https://git.kernel.org/stable/c/4eafa810b042d985ec6bbf5b514414e73cee6f6f"},{"url":"https://git.kernel.org/stable/c/8d4b989d9c9afe5f185aa5853b666fc4617afe9e"}],"tags":["cve.org"],"epss":0.0018,"epssPercentile":0.07043,"ingestedAt":"2026-10-16T19:46:24.373Z","slug":"CVE-2026-74365","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnvdimm/btt: Handle preemption in BTT lane acquisition\n\nBTT lanes serialize access to per-lane metadata and workspace state\nduring BTT I/O. The btt-check unit test reports data mismatches during\nBTT writes due to a race in lane acquisition that can lead to silent\ndata corruption.\n\nThe existing lane model uses a spinlock together with a per-CPU\nrecursion count. That recursion model stopped being valid after BTT\nlanes became preemptible: another task can run on the same CPU,\nobserve a non-zero recursion count, bypass locking, and use the same\nlane concurrently.\n\nBTT lanes are also held across arena_write_bytes() calls. That path\nreaches nsio_rw_bytes(), which flushes writes with nvdimm_flush().\nSome provider flush callbacks can sleep, making a spinlock the wrong\nprimitive for the lane lifetime.\n\nReplace the spinlock-based recursion model with a dynamically\nallocated per-lane mutex array and take the lane lock\nunconditionally.\n\nAdd might_sleep() to catch any future atomic-context caller.\n\nFound with the ndctl unit test btt-check.sh.\n\n## Affected\n\n- `Linux >= f23859748e3d530217b197e146a9ac84faf0a282 < fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735`\n- `Linux >= 6f50b414f1a0d790f11a6438a3ad6d0577eb2c18 < 73e35c1bdfa160b41fdbe204e02325f0687de506`\n- `Linux >= 36c75ce3bd299878fd9b238e9803d3817ddafbf3 < 417918783bcfe0be135019df16a267b3af442efd`\n- `Linux >= 36c75ce3bd299878fd9b238e9803d3817ddafbf3 < 5c53406098b599c420b031e6ec5ba8a2f3794c50`\n- `Linux >= 36c75ce3bd299878fd9b238e9803d3817ddafbf3 < 4eafa810b042d985ec6bbf5b514414e73cee6f6f`\n- `Linux >= 36c75ce3bd299878fd9b238e9803d3817ddafbf3 < 8d4b989d9c9afe5f185aa5853b666fc4617afe9e`\n- `Linux 2577fece583c7c05cda7ad50dde7638c962665e1`\n- `Linux 40ba3fa21250e361bdd8f00800b3e2cb6160de95`\n- `Linux b0e7a935739f33ed2bd6868b89f97dd4c2683c26`\n- `Linux 66eb7b7f23dd9aec5356e7054dd3596ae7648ff5`\n- `Linux b27751fb1f271bbb78d5993c0b10011628e40e18`\n- `Linux >= 6.1.63 < 6.1.178`\n- `Linux >= 6.6.2 < 6.6.145`\n- `Linux >= 4.19.299 < 4.20`\n- `Linux >= 5.4.261 < 5.5`\n- `Linux >= 5.10.201 < 5.11`\n- `Linux >= 5.15.139 < 5.16`\n- `Linux >= 6.5.12 < 6.6`\n- `Linux 6.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":40.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}