Time-of-check Time-of-use (TOCTOU) Race Condition in Camera Kernel Driver

The buffer obtained from kernel APIs such as cam_mem_get_cpu_buf() may be readable/writable in userspace after kernel accesses it. In other words, user mode may race and modify the packet header (e.g. header.count), causing checks (e.g. size checks) in kernel code to be invalid. This may lead to out-of-bounds read/write issues.