In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate directory-index entry counts when reading metadata
ocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and
signature of an indexed-directory block before it reaches higher-level
callers, but neither validator bounds the ocfs2_dx_entry_list counts
against the capacity of the block that holds them.
ocfs2_dx_dir_search() then walks
for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++)
dx_entry = &entry_list->de_entries[i];
over de_num_used entries with no bounds check. entry_list is either
dx_leaf->dl_list (from ocfs2_read_dx_leaf) or, for an inline root,
dx_root->dr_entries. A crafted on-disk image can set de_num_used (and
de_count, which is the __counted_by_le() bound of de_entries) to 0xffff
and make the walk read far past the end of the 4KB metadata block, giving
a slab out-of-bounds read reachable from any path lookup, stat() or open()
on an indexed directory once the image is mounted.
Commit 775c17386a6f ("ocfs2: validate dx_root extent list fields during
block read") already bounds dr_list for the non-inline dx_root, but left
the inline dr_entries path and the dx_leaf dl_list unchecked. Add the
same read-time validation for both entry lists: de_count must equal the
capacity of the block (ocfs2_dx_entries_per_leaf()/per_root()) and
de_num_used must not exceed de_count, rejecting corrupted metadata with
-EFSCORRUPTED before ocfs2_dx_dir_search() can walk an out-of-range entry
array.
de_count is always written as exactly the block capacity when a leaf or
inline root is formatted, so the equality check does not reject any valid
image.
Found by 0sec automated security-research tooling (https://0sec.ai).
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it