fs/splice.c in the splice subsystem in the Linux kernel before 2.6.22.2 does not properly handle a failure of the add_to_page_cache_lru function, and subsequently attempts to unlock a page that was not locked, which allows local users to cause a denial of service (kernel BUG and system crash), as demonstrated by the fio I/O tool.
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 |
|---|---|---|---|
| Linux_kernel | Linux | * | 2.6.22.2 (excluding) |
| Red Hat Enterprise Linux 5 | RedHat | kernel-0:2.6.18-92.1.18.el5 | * |
| Linux | Ubuntu | upstream | * |
| Linux-source-2.6.20 | Ubuntu | feisty | * |
| Linux-source-2.6.20 | Ubuntu | upstream | * |
| Linux-source-2.6.22 | Ubuntu | upstream | * |
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.