{"id":"AZL-64767","summary":"CVE-2025-38220 affecting package kernel for versions less than 6.6.96.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: only dirty folios when data journaling regular files\n\nfstest generic/388 occasionally reproduces a crash that looks as\nfollows:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\n...\nCall Trace:\n \u003cTASK\u003e\n ext4_block_zero_page_range+0x30c/0x380 [ext4]\n ext4_truncate+0x436/0x440 [ext4]\n ext4_process_orphan+0x5d/0x110 [ext4]\n ext4_orphan_cleanup+0x124/0x4f0 [ext4]\n ext4_fill_super+0x262d/0x3110 [ext4]\n get_tree_bdev_flags+0x132/0x1d0\n vfs_get_tree+0x26/0xd0\n vfs_cmd_create+0x59/0xe0\n __do_sys_fsconfig+0x4ed/0x6b0\n do_syscall_64+0x82/0x170\n ...\n\nThis occurs when processing a symlink inode from the orphan list. The\npartial block zeroing code in the truncate path calls\next4_dirty_journalled_data() -\u003e folio_mark_dirty(). The latter calls\nmapping-\u003ea_ops-\u003edirty_folio(), but symlink inodes are not assigned an\na_ops vector in ext4, hence the crash.\n\nTo avoid this problem, update the ext4_dirty_journalled_data() helper to\nonly mark the folio dirty on regular files (for which a_ops is\nassigned). This also matches the journaling logic in the ext4_symlink()\ncreation path, where ext4_handle_dirty_metadata() is called directly.","modified":"2026-04-01T05:20:23.777709Z","published":"2025-07-04T14:15:30Z","upstream":["CVE-2025-38220"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38220"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.96.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-64767.json"}}],"schema_version":"1.7.5"}