On Thu, Nov 17, 2022 at 07:53:23PM +0800, Zhen Lei wrote:
> Accessing buf->flags after pipe_buf_release(pipe, buf) is unsafe, because
> the 'buf' memory maybe freed.
Huh? What are you talking about?
struct pipe_buffer *buf = &pipe->bufs[tail & mask];
To free *buf you would need to free the entire damn array, which is
obviously not going to be possible here; if you are talking about reuse
of *buf - that's controlled by pipe->tail, and we do not assign it until
later.
Fetching any fields of *buf is safe; what can get freed is buf->page, not
buf itself. So that buf->flags access is fine.
