{"id":"CVE-2025-39759","summary":"btrfs: qgroup: fix race between quota disable and quota rescan ioctl","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: qgroup: fix race between quota disable and quota rescan ioctl\n\nThere's a race between a task disabling quotas and another running the\nrescan ioctl that can result in a use-after-free of qgroup records from\nthe fs_info-\u003eqgroup_tree rbtree.\n\nThis happens as follows:\n\n1) Task A enters btrfs_ioctl_quota_rescan() -\u003e btrfs_qgroup_rescan();\n\n2) Task B enters btrfs_quota_disable() and calls\n   btrfs_qgroup_wait_for_completion(), which does nothing because at that\n   point fs_info-\u003eqgroup_rescan_running is false (it wasn't set yet by\n   task A);\n\n3) Task B calls btrfs_free_qgroup_config() which starts freeing qgroups\n   from fs_info-\u003eqgroup_tree without taking the lock fs_info-\u003eqgroup_lock;\n\n4) Task A enters qgroup_rescan_zero_tracking() which starts iterating\n   the fs_info-\u003eqgroup_tree tree while holding fs_info-\u003eqgroup_lock,\n   but task B is freeing qgroup records from that tree without holding\n   the lock, resulting in a use-after-free.\n\nFix this by taking fs_info-\u003eqgroup_lock at btrfs_free_qgroup_config().\nAlso at btrfs_qgroup_rescan() don't start the rescan worker if quotas\nwere already disabled.","aliases":["ECHO-e03f-1992-6aab"],"modified":"2026-04-14T18:26:31.060722120Z","published":"2025-09-11T16:52:28.314Z","related":["SUSE-SU-2025:03600-1","SUSE-SU-2025:03634-1","SUSE-SU-2025:20851-1","SUSE-SU-2025:20861-1","SUSE-SU-2025:20870-1","SUSE-SU-2025:20898-1","SUSE-SU-2025:21074-1","SUSE-SU-2025:21139-1","SUSE-SU-2025:21179-1","SUSE-SU-2025:3751-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4141-1","openSUSE-SU-2025:20081-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39759.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2fd0f5ceb997f90f4332ccbab6c7e907e6b2d0eb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7cda0fdde5d9890976861421d207870500f9aace"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b172535ccba12f0cf7d23b3b840989de47fc104d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c38028ce0d0045ca600b6a8345a0ff92bfb47b66"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dd0b28d877b293b1d7f8727a7de08ae36b6b9ef0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e1249667750399a48cafcf5945761d39fa584edf"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39759.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39759"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e685da14af6b31e4b336a110cb1bae1afc268be8"},{"fixed":"7cda0fdde5d9890976861421d207870500f9aace"},{"fixed":"b172535ccba12f0cf7d23b3b840989de47fc104d"},{"fixed":"dd0b28d877b293b1d7f8727a7de08ae36b6b9ef0"},{"fixed":"c38028ce0d0045ca600b6a8345a0ff92bfb47b66"},{"fixed":"2fd0f5ceb997f90f4332ccbab6c7e907e6b2d0eb"},{"fixed":"e1249667750399a48cafcf5945761d39fa584edf"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39759.json"}}],"schema_version":"1.7.5"}