Jean-Baptiste Cayrou discovered that the shiftfs file system in the Ubuntu Linux kernel contained a race condition when handling inode locking in some situations. A local attacker could use this to cause a denial of service (kernel deadlock).
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ubuntu_linux | Canonical | 20.04 (including) | 20.04 (including) |
| Ubuntu_linux | Canonical | 22.04 (including) | 22.04 (including) |
| Ubuntu_linux | Canonical | 22.10 (including) | 22.10 (including) |
Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.