{"id":"CVE-2026-74365","state":"PUBLISHED","title":"nvdimm/btt: Handle preemption in BTT lane acquisition","description":"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 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.","publishedAt":"2026-08-15T05:58:47.594Z","updatedAt":"2026-10-16T18:55:35.765Z","severity":{"score":7.3,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f23859748e3d530217b197e146a9ac84faf0a282","status":"affected","lessThan":"fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735","versionType":"git"},{"version":"6f50b414f1a0d790f11a6438a3ad6d0577eb2c18","status":"affected","lessThan":"73e35c1bdfa160b41fdbe204e02325f0687de506","versionType":"git"},{"version":"36c75ce3bd299878fd9b238e9803d3817ddafbf3","status":"affected","lessThan":"417918783bcfe0be135019df16a267b3af442efd","versionType":"git"},{"version":"36c75ce3bd299878fd9b238e9803d3817ddafbf3","status":"affected","lessThan":"5c53406098b599c420b031e6ec5ba8a2f3794c50","versionType":"git"},{"version":"36c75ce3bd299878fd9b238e9803d3817ddafbf3","status":"affected","lessThan":"4eafa810b042d985ec6bbf5b514414e73cee6f6f","versionType":"git"},{"version":"36c75ce3bd299878fd9b238e9803d3817ddafbf3","status":"affected","lessThan":"8d4b989d9c9afe5f185aa5853b666fc4617afe9e","versionType":"git"},{"version":"2577fece583c7c05cda7ad50dde7638c962665e1","status":"affected","versionType":"git"},{"version":"40ba3fa21250e361bdd8f00800b3e2cb6160de95","status":"affected","versionType":"git"},{"version":"b0e7a935739f33ed2bd6868b89f97dd4c2683c26","status":"affected","versionType":"git"},{"version":"66eb7b7f23dd9aec5356e7054dd3596ae7648ff5","status":"affected","versionType":"git"},{"version":"b27751fb1f271bbb78d5993c0b10011628e40e18","status":"affected","versionType":"git"},{"version":"6.1.63","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.2","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"4.19.299","status":"affected","lessThan":"4.20","versionType":"semver"},{"version":"5.4.261","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.201","status":"affected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.139","status":"affected","lessThan":"5.16","versionType":"semver"},{"version":"6.5.12","status":"affected","lessThan":"6.6","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["Documentation/driver-api/nvdimm/btt.rst","drivers/nvdimm/nd.h","drivers/nvdimm/region_devs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.7","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["Documentation/driver-api/nvdimm/btt.rst","drivers/nvdimm/nd.h","drivers/nvdimm/region_devs.c"]}],"references":["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"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74365.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74365","state":"PUBLISHED","datePublished":"2026-08-15T05:58:47.594Z","dateUpdated":"2026-10-16T18:55:35.765Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.888Z"},"containers":{"cna":{"title":"nvdimm/btt: Handle preemption in BTT lane acquisition","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f23859748e3d530217b197e146a9ac84faf0a282","status":"affected","lessThan":"fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735","versionType":"git"},{"version":"6f50b414f1a0d790f11a6438a3ad6d0577eb2c18","status":"affected","lessThan":"73e35c1bdfa160b41fdbe204e02325f0687de506","versionType":"git"},{"version":"36c75ce3bd299878fd9b238e9803d3817ddafbf3","status":"affected","lessThan":"417918783bcfe0be135019df16a267b3af442efd","versionType":"git"},{"version":"36c75ce3bd299878fd9b238e9803d3817ddafbf3","status":"affected","lessThan":"5c53406098b599c420b031e6ec5ba8a2f3794c50","versionType":"git"},{"version":"36c75ce3bd299878fd9b238e9803d3817ddafbf3","status":"affected","lessThan":"4eafa810b042d985ec6bbf5b514414e73cee6f6f","versionType":"git"},{"version":"36c75ce3bd299878fd9b238e9803d3817ddafbf3","status":"affected","lessThan":"8d4b989d9c9afe5f185aa5853b666fc4617afe9e","versionType":"git"},{"version":"2577fece583c7c05cda7ad50dde7638c962665e1","status":"affected","versionType":"git"},{"version":"40ba3fa21250e361bdd8f00800b3e2cb6160de95","status":"affected","versionType":"git"},{"version":"b0e7a935739f33ed2bd6868b89f97dd4c2683c26","status":"affected","versionType":"git"},{"version":"66eb7b7f23dd9aec5356e7054dd3596ae7648ff5","status":"affected","versionType":"git"},{"version":"b27751fb1f271bbb78d5993c0b10011628e40e18","status":"affected","versionType":"git"},{"version":"6.1.63","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.2","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"4.19.299","status":"affected","lessThan":"4.20","versionType":"semver"},{"version":"5.4.261","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.201","status":"affected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.139","status":"affected","lessThan":"5.16","versionType":"semver"},{"version":"6.5.12","status":"affected","lessThan":"6.6","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["Documentation/driver-api/nvdimm/btt.rst","drivers/nvdimm/nd.h","drivers/nvdimm/region_devs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.7","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["Documentation/driver-api/nvdimm/btt.rst","drivers/nvdimm/nd.h","drivers/nvdimm/region_devs.c"]}],"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"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L","baseScore":7.3,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The flaw is reached only through local block I/O on a BTT-backed /dev/pmem* device via vfs_write/pwrite/O_DIRECT paths into btt_submit_bio->btt_write_pg/btt_read_pg->nd_region_acquire_lane; it is not in a network protocol handler.\nAC:L - After BTT lanes became preemptible, a second task on the same CPU can bypass the per-CPU recursion spinlock while the first still holds the lane across sleeping arena_write_bytes/nvdimm_flush; an attacker reliably wins by issuing concurrent writes (e.g., many threads) to the BTT block device.\nPR:L - No capability checks exist on the bio submission path; any local principal with write access to the BTT block device or a filesystem mounted on it (common for database/service accounts on PMEM servers) can trigger the race without real init-namespace root.\nUI:N - Exploitation requires only automated concurrent block writes from the attacker-controlled process and does not depend on any victim user opening files, clicking prompts, or performing other interactive actions.\nS:U - Impact is confined to corrupting BTT metadata and data within the attacker's reachable persistent-memory namespace on the same host; it does not cross VM, container, or IOMMU security boundaries to affect other security authorities.\nC:H - Unserialized lane use corrupts BTT map/log/freelist and in-memory arena->rtt/freelist state, so reads can return stale or mis-mapped sector contents (cross-LBA disclosure); the ndctl btt-check test observed data mismatches confirming readable integrity loss.\nI:H - Concurrent writers can silently corrupt on-media BTT translation tables and user data blocks, producing arbitrary persistent storage modification rather than a bounded or detectable single-field change, matching the fix commit's silent data-corruption description.\nA:L - The primary failure mode is silent corruption and subsequent I/O errors on the affected namespace rather than a kernel panic or hang, but corrupted BTT metadata can persistently degrade or deny reliable access to the volume until recovery or rebuild."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:46:24.251Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.63","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.2","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.299"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.201"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.139"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5.12"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74365","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:54:37.742896Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:55:35.765Z"}}]}}}