The pfs_getextattr function in FreeBSD 7.x before 7.3-RELEASE and 8.x before 8.0-RC1 unlocks a mutex that was not previously locked, which allows local users to cause a denial of service (kernel panic), overwrite arbitrary memory locations, and possibly execute arbitrary code via vectors related to opening a file on a file system that uses pseudofs.
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 |
|---|---|---|---|
| Freebsd | Freebsd | 7.0 (including) | 7.3 (excluding) |
| Freebsd | Freebsd | 8.0-p1 (including) | 8.0-p1 (including) |
| Freebsd | Freebsd | 8.0-p2 (including) | 8.0-p2 (including) |
| Freebsd | Freebsd | 8.0-p3 (including) | 8.0-p3 (including) |
| Freebsd | Freebsd | 8.0-p4 (including) | 8.0-p4 (including) |
| Freebsd | Freebsd | 8.0-p5 (including) | 8.0-p5 (including) |
| Freebsd | Freebsd | 8.0-p6 (including) | 8.0-p6 (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.