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.
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.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 28 Aug 2026 11:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-125 CWE-20 |
Fri, 28 Aug 2026 07:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | ntfs: bound the look-ahead attribute-list entry in ntfs_external_attr_find() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-28T06:49:12.951Z
Reserved: 2026-08-26T14:34:25.782Z
Link: CVE-2026-80673
No data.
Status : Received
Published: 2026-08-28T08:16:52.607
Modified: 2026-08-28T08:16:52.607
Link: CVE-2026-80673
No data.
OpenCVE Enrichment
Updated: 2026-08-28T10:45:04Z