In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: hold io_buffer_list reference over mmap If we look up the kbuf, ensure that it doesn't get unregistered until after we're done with it. Since we're inside mmap, we cannot safely use the io_uring lock. Rely on the fact that we can lookup the buffer list under RCU now and grab a reference to it, preventing it from being unregistered until we're done with it. The lookup returns the io_buffer_list directly with it referenced.
https://git.kernel.org/stable/c/65938e81df2197203bda4b9a0c477e7987218d66
https://git.kernel.org/stable/c/5fd8e2359498043e0b5329a05f02d10a9eb91eb9
https://git.kernel.org/stable/c/561e4f9451d65fc2f7eef564e0064373e3019793