Vulnerability details

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordData{Root,Allocation} In do_action()'s UpdateRecordDataRoot (fslog.c:3489) and UpdateRecordDataAllocation (fslog.c:3697) cases, the memmove destination is `Add2Ptr(e, le16_to_cpu(e->view.data_off))`, where e->view.data_off comes from an on-disk NTFS_DE inside an INDEX_ROOT or INDEX_BUFFER. Neither case validates view.data_off + dlen against e->size; the existing check_if_index_root / check_if_alloc_index helpers walk the entry chain and validate the entry's offset, but not its internal view fields. The neighbouring read sites (e.g., fs/ntfs3/index.c when iterating view entries) check view.data_off + view.data_size <= e->size. Apply the same bound at the two memmove sites. Reproduced under UML+KASAN on mainline 8d90b09e6741 via pr_warn-only probe instrumentation: with view.data_off forced to 0xFFFC, the memmove writes 32 bytes past the end of the NTFS_DE. This is similar in shape to Pavitra Jha's 2026-05-02 patch "fs/ntfs3: prevent oob in case UpdateRecordDataRoot" (<20260502105008.21827-1-jhapavitra98@gmail.com>) which proposes calling ntfs3_bad_de_range(); that helper does not exist in mainline. This patch uses inline checks.

• https://git.kernel.org/stable/c/b20e5a709d8bd190d6e4645606763c7423e694c1
• https://git.kernel.org/stable/c/d41b382068ca4e64e421f736cdd700095464b6ac
• https://git.kernel.org/stable/c/429d653ca641d38a78609b8f62e81a0a5c780a2d
• https://git.kernel.org/stable/c/315d3a9a48b49f889da3d858a9307e677cb9e1bd
• https://git.kernel.org/stable/c/be306b8d9143a9c076c804a7ca025d69caf9c448
• https://git.kernel.org/stable/c/36feda687afebae24c472202694448738809c411
• https://git.kernel.org/stable/c/3e127829e57f5190f612412ece4541cb96d5ec7a