Withdrawn by the publisher.

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

ntfs: validate resident attribute lists and harden the validator

A base inode's $ATTRIBUTE_LIST is sanity-checked by load_attribute_list() only on the non-resident path; ntfs_read_locked_inode() copies a *resident* attribute list into ni->attr_list with a plain memcpy() and no validation at all. Every subsequent walk of ni->attr_list -- ntfs_external_attr_find(), ntfs_inode_attach_all_extents() and ntfs_attrlist_need() -- then trusts the entries are well-formed and reads attr_list_entry fixed-header fields (lowest_vcn at offset 8, mft_reference at offset 16, and the name) with bounds that assume validation already happened. A crafted resident attribute list therefore reaches those walks unvalidated and can drive out-of-bounds reads of the attribute-list buffer.

load_attribute_list() itself reads ale->name_offset (offset 7), ale->mft_reference (offset 16) and the name length under only an "al < al_start + size" bound, so its own validation loop can over-read the fixed header of a truncated trailing entry by a few bytes.

Factor the per-entry validation into ntfs_attr_list_entry_is_valid(), which requires each entry's fixed header (offsetof(struct attr_list_entry, name)) to be in range before any field is dereferenced, that ale->length is a multiple of 8 covering the fixed header plus the name, and that the entry is in use and carries a live MFT reference. ntfs_attr_list_is_valid() walks the buffer with it…

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

ntfs: validate resident attribute lists and harden the validator

A base inode's $ATTRIBUTE_LIST is sanity-checked by load_attribute_list() only on the non-resident path; ntfs_read_locked_inode() copies a *resident* attribute list into ni->attr_list with a plain memcpy() and no validation at all. Every subsequent walk of ni->attr_list -- ntfs_external_attr_find(), ntfs_inode_attach_all_extents() and ntfs_attrlist_need() -- then trusts the entries are well-formed and reads attr_list_entry fixed-header fields (lowest_vcn at offset 8, mft_reference at offset 16, and the name) with bounds that assume validation already happened. A crafted resident attribute list therefore reaches those walks unvalidated and can drive out-of-bounds reads of the attribute-list buffer.

load_attribute_list() itself reads ale->name_offset (offset 7), ale->mft_reference (offset 16) and the name length under only an "al < al_start + size" bound, so its own validation loop can over-read the fixed header of a truncated trailing entry by a few bytes.

Factor the per-entry validation into ntfs_attr_list_entry_is_valid(), which requires each entry's fixed header (offsetof(struct attr_list_entry, name)) to be in range before any field is dereferenced, that ale->length is a multiple of 8 covering the fixed header plus the name, and that the entry is in use and carries a live MFT reference. ntfs_attr_list_is_valid() walks the buffer with it…

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 95 more

In the Linux kernel, the following vulnerability has been resolved: ntfs: validate resident attribute lists and harden the validator A base inode's $ATTRIBUTE_LIST is sanity-checked by load_attribute_list() only on the non-resident path; ntfs_read_locked_inode() copies a *resident* attribute list into ni->attr_list with a plain memcpy() and no validation at all. Every subsequent walk of ni->attr_list -- ntfs_external_attr_find(), ntfs_inode_attach_all_extents() and ntfs_attrlist_need() -- then trusts the entries are well-formed and reads attr_list_entry fixed-header fields (lowest_vcn at offset 8, mft_reference at offset 16, and the name) with bounds that assume validation already happened. A crafted resident attribute list therefore reaches those walks unvalidated and can drive out-of-bounds reads of the attribute-list buffer. load_attribute_list() itself reads ale->name_offset (offset 7), ale->mft_reference (offset 16) and the name length under only an "al < al_start + size" bound, so its own validation loop can over-read the fixed header of a truncated trailing entry by a few bytes. Factor the per-entry validation into ntfs_attr_list_entry_is_valid(), which requires each entry's fixed header (offsetof(struct attr_list_entry, name)) to be in range before any field is dereferenced, that ale->length is a multiple of 8 covering the fixed header plus the name, and that the entry is in use and carries a live MFT reference. ntfs_attr_list_is_valid() walks the buffer with it and…

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, darunter möglicherweise Speicherbeschädigungen, die Offenlegung oder Manipulation von Daten sowie Denial-of-Service-Zustände.