CVE-2026-74365
HighCVSS 7.3Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
In the Linux kernel, a vulnerability in the BTT (Block Translation Table) mechanism for NVDIMM has been fixed, related to preemption during lane acquisition. The previous spinlock-based recursion model was invalid after lanes became preemptible, potentially leading to silent data corruption. The fix replaces the spinlock with a dynamically allocated per-lane mutex array.
Risk Assessment
The vulnerability could lead to silent data corruption during writes to NVDIMM, potentially causing data integrity issues and hard-to-detect errors.
Recommendation
Update the Linux kernel to a patched version and run ndctl unit tests (e.g., btt-check.sh) to verify correct operation.
Original NVD description (English source)
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.