{"cve":"CVE-2023-53618","nvd":{"published":"2025-10-07T16:15:44.297","modified":"2026-06-17T06:45:43.750","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: reject invalid reloc tree root keys with stack dump\n\n[BUG]\nSyzbot reported a crash that an ASSERT() got triggered inside\nprepare_to_merge().\n\nThat ASSERT() makes sure the reloc tree is properly pointed back by its\nsubvolume tree.\n\n[CAUSE]\nAfter more debugging output, it turns out we had an invalid reloc tree:\n\n  BTRFS error (device loop1): reloc tree mismatch, root 8 has no reloc root, expect reloc root key (-8, 132, 8) gen 17\n\nNote the above root key is (TREE_RELOC_OBJECTID, ROOT_ITEM,\nQUOTA_TREE_OBJECTID), meaning it's a reloc tree for quota tree.\n\nBut reloc trees can only exist for subvolumes, as for non-subvolume\ntrees, we just COW the involved tree block, no need to create a reloc\ntree since those tree blocks won't be shared with other trees.\n\nOnly subvolumes tree can share tree blocks with other trees (thus they\nhave BTRFS_ROOT_SHAREABLE flag).\n\nThus this new debug output proves my previous assumption that corrupted\non-disk data can trigger that ASSERT().\n\n[FIX]\nBesides the dedicated fix and the graceful exit, also let tree-checker to\ncheck such root keys, to make sure reloc trees can only exist for subvolumes.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/314135b7bae9618a317874ae195272682cf2d5d4","https://git.kernel.org/stable/c/3ae93b316ca4b8b3c33798ef1d210355f2fb9318","https://git.kernel.org/stable/c/6ebcd021c92b8e4b904552e4d87283032100796d","https://git.kernel.org/stable/c/84256e00eeca73c529fc6196e478cc89b8098157"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:11:26.888974865+00:00"},"epss":{"cve":"CVE-2023-53618","score":0.00202,"percentile":0.10164,"date":"2026-10-31"},"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."]}