CVE-2025-68774
CVE-2025-68774CVE-2025-68774
Description
In the Linux kernel, the following vulnerability has been resolved:
hfsplus: fix missing hfs_bnode_get() in __hfs_bnode_create
When sync() and link() are called concurrently, both threads may
enter hfs_bnode_find() without finding the node in the hash table
and proceed to create it.
Thread A:
hfsplus_write_inode()
-> hfsplus_write_system_inode()
-> hfs_btree_write()
-> hfs_bnode_find(tree, 0)
-> __hfs_bnode_create(tree, 0)
Thread B:
hfsplus_create_cat()
-> hfs_brec_insert()
-> hfs_bnode_split()
-> hfs_bmap_alloc()
-> hfs_bnode_find(tree, 0)
-> __hfs_bnode_create(tree, 0)
In this case, thread A creates the bnode, sets refcnt=1, and hashes it.
Thread B also tries to create the same bnode, notices it has already
been inserted, drops its own instance, and uses the hashed one without
getting the node.
```
node2 = hfs_bnode_findhash(tree, cnid);
if (!node2) { <- Thread A
hash =
Scoring
| CVSS | 7.5 () |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Last modified | 2026-07-30 |