{"id":"DEBIAN-CVE-2025-38220","details":"In the Linux kernel, the following vulnerability has been resolved:  ext4: only dirty folios when data journaling regular files  fstest generic/388 occasionally reproduces a crash that looks as follows:  BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace:  \u003cTASK\u003e  ext4_block_zero_page_range+0x30c/0x380 [ext4]  ext4_truncate+0x436/0x440 [ext4]  ext4_process_orphan+0x5d/0x110 [ext4]  ext4_orphan_cleanup+0x124/0x4f0 [ext4]  ext4_fill_super+0x262d/0x3110 [ext4]  get_tree_bdev_flags+0x132/0x1d0  vfs_get_tree+0x26/0xd0  vfs_cmd_create+0x59/0xe0  __do_sys_fsconfig+0x4ed/0x6b0  do_syscall_64+0x82/0x170  ...  This occurs when processing a symlink inode from the orphan list. The partial block zeroing code in the truncate path calls ext4_dirty_journalled_data() -\u003e folio_mark_dirty(). The latter calls mapping-\u003ea_ops-\u003edirty_folio(), but symlink inodes are not assigned an a_ops vector in ext4, hence the crash.  To avoid this problem, update the ext4_dirty_journalled_data() helper to only mark the folio dirty on regular files (for which a_ops is assigned). This also matches the journaling logic in the ext4_symlink() creation path, where ext4_handle_dirty_metadata() is called directly.","modified":"2026-08-27T23:05:29.539859890Z","published":"2025-07-04T14:15:30.597Z","upstream":["CVE-2025-38220"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2025-38220"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.35-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-38220.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.35-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-38220.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}