{"cve":"CVE-2025-39884","nvd":{"published":"2025-09-23T06:15:48.227","modified":"2026-10-19T21:10:00.160","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix subvolume deletion lockup caused by inodes xarray race\n\nThere is a race condition between inode eviction and inode caching that\ncan cause a live struct btrfs_inode to be missing from the root->inodes\nxarray. Specifically, there is a window during evict() between the inode\nbeing unhashed and deleted from the xarray. If btrfs_iget() is called\nfor the same inode in that window, it will be recreated and inserted\ninto the xarray, but then eviction will delete the new entry, leaving\nnothing in the xarray:\n\nThread 1                          Thread 2\n---------------------------------------------------------------\nevict()\n  remove_inode_hash()\n                                  btrfs_iget_path()\n                                    btrfs_iget_locked()\n                                    btrfs_read_locked_inode()\n                                      btrfs_add_inode_to_root()\n  destroy_inode()\n    btrfs_destroy_inode()\n      btrfs_del_inode_from_root()\n        __xa_erase\n\nIn turn, this can cause issues for subvolume deletion. Specifically, if\nan inode is in this lost state, and all other inodes are evicted, then\nbtrfs_del_inode_from_root() will call btrfs_add_dead_root() prematurely.\nIf the lost inode has a delayed_node attached to it, then when\nbtrfs_clean_one_deleted_snapshot() calls btrfs_kill_all_delayed_nodes(),\nit will loop forever because the delayed_nodes xarray will never become\nempty (unless memory pressure forces the inode out). We saw this\nmanifest as soft lockups in production.\n\nFix it by only deleting the xarray entry if it matches the given inode\n(using __xa_cmpxchg()).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","score":4.7},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/9ba898c9fcbe6ebb88bcd4df8aab0f90090d202e","https://git.kernel.org/stable/c/f1498abaf74f8d7b1e7001f16ed77818d8ae6a59","https://git.kernel.org/stable/c/f6a6c280059c4ddc23e12e3de1b01098e240036f"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-39884","score":0.00108,"percentile":0.01195,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}