{"id":"CVE-2026-74365","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74365","summary":"nvdimm/btt: Handle preemption in BTT lane acquisition","details":"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.","published":"2026-08-15T05:58:47.594Z","modified":"2026-08-18T03:56:29.719598572Z","cvss":{"score":7.3,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.1.178"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/417918783bcfe0be135019df16a267b3af442efd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4eafa810b042d985ec6bbf5b514414e73cee6f6f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5c53406098b599c420b031e6ec5ba8a2f3794c50"},{"type":"WEB","url":"https://git.kernel.org/stable/c/73e35c1bdfa160b41fdbe204e02325f0687de506"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8d4b989d9c9afe5f185aa5853b666fc4617afe9e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fd7a97b2514cfc4b4cc067a27dd39bde2a8b1735"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74365.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74365"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:29.719598572Z"}}