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CVE PROGRAM SOURCE RECORD7.3 High

CVE-2026-74365

nvdimm/btt: Handle preemption in BTT lane acquisition

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Status
Published
Published
Updated
Assigning organization
Linux

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • f23859748e3d530217b197e146a9ac84faf0a282 to < fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735affected
  • 6f50b414f1a0d790f11a6438a3ad6d0577eb2c18 to < 73e35c1bdfa160b41fdbe204e02325f0687de506affected
  • 36c75ce3bd299878fd9b238e9803d3817ddafbf3 to < 417918783bcfe0be135019df16a267b3af442efdaffected
  • 36c75ce3bd299878fd9b238e9803d3817ddafbf3 to < 5c53406098b599c420b031e6ec5ba8a2f3794c50affected
  • 36c75ce3bd299878fd9b238e9803d3817ddafbf3 to < 4eafa810b042d985ec6bbf5b514414e73cee6f6faffected
  • 36c75ce3bd299878fd9b238e9803d3817ddafbf3 to < 8d4b989d9c9afe5f185aa5853b666fc4617afe9eaffected
  • 2577fece583c7c05cda7ad50dde7638c962665e1affected
  • 40ba3fa21250e361bdd8f00800b3e2cb6160de95affected
  • b0e7a935739f33ed2bd6868b89f97dd4c2683c26affected
  • 66eb7b7f23dd9aec5356e7054dd3596ae7648ff5affected
  • b27751fb1f271bbb78d5993c0b10011628e40e18affected
  • 6.1.63 to < 6.1.178affected
  • 6.6.2 to < 6.6.145affected
  • 4.19.299 to < 4.20affected
  • 5.4.261 to < 5.5affected
  • 5.10.201 to < 5.11affected
  • 5.15.139 to < 5.16affected
  • 6.5.12 to < 6.6affected

Linux Linux

Default version status: affected

  • 6.7affected
  • 0 to < 6.7unaffected
  • 6.1.178 to ≤ 6.1.*unaffected
  • 6.6.145 to ≤ 6.6.*unaffected
  • 6.12.97 to ≤ 6.12.*unaffected
  • 6.18.40 to ≤ 6.18.*unaffected
  • 7.1.5 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References