In the Linux kernel, the following vulnerability has been resolved:NFS: Fix a race when updating an existing writeAfter nfs_lock_and_join_requests() tests for whether the request isstill attached to the mapping, nothing prevents a call tonfs_inode_remove_request() from succeeding until we actually lock thepage group.The reason is that whoever called nfs_inode_remove_request() doesn'tnecessarily have a lock on the page group head.So in order to avoid races, let's take the page group lock earlier innfs_lock_and_join_requests(), and hold it across the removal of therequest in nfs_inode_remove_request().
No PoCs from references.
- https://github.com/w4zu/Debian_security