ocfs2: validate directory-index entry counts when reading metadata
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.6.160, 6.12.111, 6.18.51, 7.2.4
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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).
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 9b7895efac906d66d19856194e1ba61f37e231a4 · fixed in aad3129b8e915d0ff492bb7517d825d8490cfdd9; From 9b7895efac906d66d19856194e1ba61f37e231a4 · fixed in 5e661f55ca8568471fce558effe81cca112f5cb2; From 9b7895efac906d66d19856194e1ba61f37e231a4 · fixed in fcfcba8fe17dbf2c8805690b8cc25e32d81249a4; From 9b7895efac906d66d19856194e1ba61f37e231a4 · fixed in b8a5c0c32df2c5b685ceef76ac77e37c7e1dc3ed; From 9b7895efac906d66d19856194e1ba61f37e231a4 · fixed in bc70726ddad53c7e9a9a85915bf2415b0d4f42f9
- Linux Linux
2.6.30
- KernelLinux
From 2.6.30 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.4