In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ntfs: validate attribute values on lookup<\/p>\n
ntfs_attr_find() and ntfs_external_attr_find() check that generic
\nresident attribute values fit in their attribute records and that
\nfixed-size resident values are large enough. For variable-length resident
\nformats, however, the fixed part is not enough: embedded length fields
\ncan still point callers past the resident value.<\/p>\n
A crafted image can set a small resident $FILE_NAME value_length while
\nleaving file_name_length large. Callers then trust file_name_length and
\nread past the resident value when converting or comparing the name. This
\nwas reproduced with a crafted image under KASAN as a slab-out-of-bounds
\nread from the kmalloc-1k MFT record copy. The stack included
\nntfs_lookup(), ntfs_iget(), ntfs_read_locked_inode(), ntfs_attr_name_get(),
\nntfs_ucstonls(), and utf16s_to_utf8s().<\/p>\n
Add a shared attribute value validator and use it before a lookup path
\ncan return an attribute, including the AT_UNUSED enumeration case where
\ncallers inspect returned attributes directly. The helper validates
\nresident value bounds, minimum resident value sizes, variable-length
\n$FILE_NAME fields, and non-resident mapping-pairs metadata that was
\npreviously checked separately in both lookup paths.<\/p>\n
This also preserves the intended resident @val matching semantics in the
\nexternal attribute lookup path. The old duplicated validation block
\noverwrote the actual resident value length with the type-specific minimum
\nlength before comparing @val, so variable-length resident values could
\nfail to match even when the bytes were identical. Keep the comparison on
\nthe actual value length, and make ntfs_attrlist_entry_add() compare
\nresident attributes with lowest_vcn zero instead of reading the
\nnon-resident union member after a successful resident match.<\/p>\n
Reject non-resident $FILE_NAME records too: the format requires
\n$FILE_NAME to be resident and callers treat returned records as resident.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ntfs: validate attribute values on lookup<\/p>\n
ntfs_attr_find() and ntfs_external_attr_find() check that generic
\nresident attribute val<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-6839","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/6839","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6839"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6839"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6839"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}