CVE-2026-80673 PUBLISHED

ntfs: bound the look-ahead attribute-list entry in ntfs_external_attr_find()

Assigner: Linux
Reserved: 26.08.2026 Published: 28.08.2026 Updated: 28.08.2026

In the Linux kernel, the following vulnerability has been resolved:

ntfs: bound the look-ahead attribute-list entry in ntfs_external_attr_find()

When resolving an attribute lookup with a non-zero @lowest_vcn, ntfs_external_attr_find() peeks at the next $ATTRIBUTE_LIST entry to decide whether to keep searching, but bounds that not-yet-validated entry only with "(u8 )next_al_entry + 6 < al_end" (which proves just bytes 0..6 are in range) and "(u8 )next_al_entry + length <= al_end" with an attacker-controlled, non-8-aligned length. It then reads next_al_entry->lowest_vcn (an __le64 at offset 8) and the name at next_al_entry->name_offset, both of which can lie past al_end -- the exact end of the kvmalloc'd attribute-list buffer (allocated at the on-disk attr_list_size, no rounding). A crafted on-disk $ATTRIBUTE_LIST whose last entry sits a few bytes before al_end therefore yields a slab out-of-bounds read when the inode is read.

Validate the look-ahead entry with ntfs_attr_list_entry_is_valid() (added in patch 1/3) before dereferencing lowest_vcn and the name, so the same fixed-header, length and name bounds the main attribute-list walk uses now guard this read too.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 1e9ea7e04472d4e5e12e58c881eaacfb3e49b669 to 44885c9b45eb4082fb7f558590d84bb254a08e94 (excl.)
  • affected from 1e9ea7e04472d4e5e12e58c881eaacfb3e49b669 to 344b18f389f9934d59c7b0cf3d20541ea2e0da58 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 7.1 is affected
  • unaffected from 0 to 7.1 (excl.)
  • unaffected from 7.1.5 to 7.1.* (incl.)
  • unaffected from 7.2 to * (incl.)

References