{"cve":"CVE-2023-52897","nvd":{"published":"2024-08-21T07:15:06.120","modified":"2026-06-17T06:43:53.187","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: qgroup: do not warn on record without old_roots populated\n\n[BUG]\nThere are some reports from the mailing list that since v6.1 kernel, the\nWARN_ON() inside btrfs_qgroup_account_extent() gets triggered during\nrescan:\n\n  WARNING: CPU: 3 PID: 6424 at fs/btrfs/qgroup.c:2756 btrfs_qgroup_account_extents+0x1ae/0x260 [btrfs]\n  CPU: 3 PID: 6424 Comm: snapperd Tainted: P           OE      6.1.2-1-default #1 openSUSE Tumbleweed 05c7a1b1b61d5627475528f71f50444637b5aad7\n  RIP: 0010:btrfs_qgroup_account_extents+0x1ae/0x260 [btrfs]\n  Call Trace:\n   <TASK>\n  btrfs_commit_transaction+0x30c/0xb40 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6]\n   ? start_transaction+0xc3/0x5b0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6]\n  btrfs_qgroup_rescan+0x42/0xc0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6]\n   btrfs_ioctl+0x1ab9/0x25c0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6]\n   ? __rseq_handle_notify_resume+0xa9/0x4a0\n   ? mntput_no_expire+0x4a/0x240\n   ? __seccomp_filter+0x319/0x4d0\n   __x64_sys_ioctl+0x90/0xd0\n   do_syscall_64+0x5b/0x80\n   ? syscall_exit_to_user_mode+0x17/0x40\n   ? do_syscall_64+0x67/0x80\n  entry_SYSCALL_64_after_hwframe+0x63/0xcd\n  RIP: 0033:0x7fd9b790d9bf\n   </TASK>\n\n[CAUSE]\nSince commit e15e9f43c7ca (\"btrfs: introduce\nBTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING to skip qgroup accounting\"), if\nour qgroup is already in inconsistent state, we will no longer do the\ntime-consuming backref walk.\n\nThis can leave some qgroup records without a valid old_roots ulist.\nNormally this is fine, as btrfs_qgroup_account_extents() would also skip\nthose records if we have NO_ACCOUNTING flag set.\n\nBut there is a small window, if we have NO_ACCOUNTING flag set, and\ninserted some qgroup_record without a old_roots ulist, but then the user\ntriggered a qgroup rescan.\n\nDuring btrfs_qgroup_rescan(), we firstly clear NO_ACCOUNTING flag, then\ncommit current transaction.\n\nAnd since we have a qgroup_record with old_roots = NULL, we trigger the\nWARN_ON() during btrfs_qgroup_account_extents().\n\n[FIX]\nUnfortunately due to the introduction of NO_ACCOUNTING flag, the\nassumption that every qgroup_record would have its old_roots populated\nis no longer correct.\n\nFix the false alerts and drop the WARN_ON().","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":[],"references":["https://git.kernel.org/stable/c/75181406b4eafacc531ff2ee5fb032bd93317e2b","https://git.kernel.org/stable/c/bb2c2e62539f2b63c5e0beb51501d328260c7595"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:54:16.205165117+00:00"},"epss":{"cve":"CVE-2023-52897","score":0.00198,"percentile":0.0966,"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."]}