{"id":"AZL-96168","summary":"CVE-2026-72203 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: skip extent mft records in writeback to prevent deadlock\n\nThis patch fixes the ABBA deadlock between extent_lock and extent\nmrec_lock triggered by xfstests generic/113, that occurs since the commit\n6994acf33bae (\"ntfs: use base mft_no when looking up base inode for\n\t\textent record\").\n\nPath A (inode writeback):\n  VFS writeback\n    -\u003e ntfs_write_inode()\n      -\u003e __ntfs_write_inode()\n        -\u003e mutex_lock(&ni-\u003eextent_lock)\n        -\u003e mutex_lock(&tni-\u003emrec_lock)\n\nPath B (MFT folio writeback):\n  VFS writeback of $MFT dirty folios\n    -\u003e ntfs_mft_writepages()\n      -\u003e ntfs_write_mft_block()\n        -\u003e ntfs_may_write_mft_record()\n          -\u003e holds one extent mrec_lock from a previous iteration\n          -\u003e tries to acquire another base inode extent_lock\n\nBy removing all extent_lock and extent mrec_lock acquisition from the MFT\nfolio writeback path, the ABBA lock ordering is eliminated:\n\nPath A: __ntfs_write_inode(): extent_lock -\u003e mrec_lock\nPath B (removed): ntfs_write_mft_block(): mrec_lock -\u003e extent_lock\n\nPath B is always redundant for extent records because:\n\n1. mark_mft_record_dirty(ext_ni) does NOT dirty the MFT folio.\n   It only sets NInoDirty(ext_ni) and marks the base VFS inode dirty\n   via __mark_inode_dirty(I_DIRTY_DATASYNC), which triggers Path A.\n   Therefore, normal extent modifications never create a situation where\n   the MFT folio is dirty and Path B is not scheduled.\n\n2. The MFT folio only gets dirtied via ntfs_mft_mark_dirty() inside\n   ntfs_mft_record_alloc(). But all identified callers in attrib.c\n   (ntfs_attr_add, ntfs_attr_record_move_away,\n   ntfs_attr_make_non_resident, ntfs_attr_record_resize) follow through\n   with mark_mft_record_dirty(), which triggers Path A to write the\n   complete record.\n\n3. ntfs_evict_big_inode() calls ntfs_commit_inode() before freeing extent\n   inodes, ensuring all dirty extents are flushed via Path A before the\n   base inode leaves the icache.","modified":"2026-09-04T05:27:10Z","published":"2026-08-15T06:21:38Z","upstream":["CVE-2026-72203"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72203"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-96168.json"}}],"schema_version":"1.9.0"}