CVE-2026-72368cachefiles: Fix double unlock in nomem_d_alloc error path

Official description

In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix double unlock in nomem_d_alloc error path When start_creating() fails and returns -ENOMEM, it has already released the parent directory lock in __start_dirop(): static struct dentry *__start_dirop(...) { ... inode_lock_nested(dir, I_MUTEX_PARENT); dentry = lookup_one_qstr_excl(name, parent, lookup_flags); if (IS_ERR(dentry)) inode_unlock(dir); <-- Lock released on error return dentry; } However, the nomem_d_alloc error path in cachefiles_get_directory() unconditionally calls inode_unlock(d_inode(dir)) again, causing a double unlock that corrupts the rwsem state. This is a leftover from commit 7ab96df840e60 which replaced manual locking with start_creating() but failed to update the nomem_d_alloc path (while correctly updating mkdir_error and lookup_error paths).

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/26757dac15175f2a42e3537f1ba86e62456d48f1
• https://git.kernel.org/stable/c/8c256fba2b46020004201c500b2a1fbc707a33ef