The coredump implementation in the Linux kernel before 5.0.10 does not use locking or other mechanisms to prevent vma layout or vma flags changes while it runs, which allows local users to obtain sensitive information, cause a denial of service, or possibly have unspecified other impact by triggering a race condition with mmget_not_zero or get_task_mm calls. This is related to fs/userfaultfd.c, mm/mmap.c, fs/proc/task_mmu.c, and drivers/infiniband/core/uverbs_main.c.
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 | 2.16.12 (including) | 3.16.66 (excluding) |
| Linux_kernel | Linux | 3.17 (including) | 4.4.183 (excluding) |
| Linux_kernel | Linux | 4.5 (including) | 4.9.188 (excluding) |
| Linux_kernel | Linux | 4.10 (including) | 4.14.114 (excluding) |
| Linux_kernel | Linux | 4.15 (including) | 4.19.37 (excluding) |
| Linux_kernel | Linux | 4.20 (including) | 5.0.10 (excluding) |
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.