In the Linux kernel, the following vulnerability has been resolved: nvme: move stopping keep-alive into nvme_uninit_ctrl() Commit 4733b65d82bd ("nvme: start keep-alive after admin queue setup") moves starting keep-alive from nvme_start_ctrl() into nvme_init_ctrl_finish(), but don't move stopping keep-alive into nvme_uninit_ctrl(), so keep-alive work can be started and keep pending after failing to start controller, finally use-after-free is triggered if nvme host driver is unloaded. This patch fixes kernel panic when running nvme/004 in case that connection failure is triggered, by moving stopping keep-alive into nvme_uninit_ctrl(). This way is reasonable because keep-alive is now started in nvme_init_ctrl_finish().
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.