In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ocfs2: validate directory-index entry counts when reading metadata<\/p>\n
ocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and
\nsignature of an indexed-directory block before it reaches higher-level
\ncallers, but neither validator bounds the ocfs2_dx_entry_list counts
\nagainst the capacity of the block that holds them.<\/p>\n
ocfs2_dx_dir_search() then walks<\/p>\n
\tfor (i = 0; i de_num_used); i++)
\n\t\tdx_entry = &entry_list->de_entries[i];<\/p>\n
over de_num_used entries with no bounds check. entry_list is either
\ndx_leaf->dl_list (from ocfs2_read_dx_leaf) or, for an inline root,
\ndx_root->dr_entries. A crafted on-disk image can set de_num_used (and
\nde_count, which is the __counted_by_le() bound of de_entries) to 0xffff
\nand make the walk read far past the end of the 4KB metadata block, giving
\na slab out-of-bounds read reachable from any path lookup, stat() or open()
\non an indexed directory once the image is mounted.<\/p>\n
Commit 775c17386a6f (“ocfs2: validate dx_root extent list fields during
\nblock read”) already bounds dr_list for the non-inline dx_root, but left
\nthe inline dr_entries path and the dx_leaf dl_list unchecked. Add the
\nsame read-time validation for both entry lists: de_count must equal the
\ncapacity of the block (ocfs2_dx_entries_per_leaf()\/per_root()) and
\nde_num_used must not exceed de_count, rejecting corrupted metadata with
\n-EFSCORRUPTED before ocfs2_dx_dir_search() can walk an out-of-range entry
\narray.<\/p>\n
de_count is always written as exactly the block capacity when a leaf or
\ninline root is formatted, so the equality check does not reject any valid
\nimage.<\/p>\n
Found by 0sec automated security-research tooling (https:\/\/0sec.ai).<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ocfs2: validate directory-index entry counts when reading metadata<\/p>\n
ocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21414","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21414","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=21414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21414"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}