[Linaro-mm-sig] Re: [RFC PATCH] procfs: Add file path and size to /proc/<pid>/fdinfo

On Thu, May 19, 2022 at 6:50 PM Kees Cook keescook@chromium.org wrote:

On Thu, May 19, 2022 at 02:40:15PM -0700, Kalesh Singh wrote:

...

[...]

• seq_file_path(m, file, "\n");
  

• seq_putc(m, '\n');
  
  /* show_fd_locks() never deferences files so a stale value is safe */
  show_fd_locks(m, file, files);
  

This comment implies "file" might be stale? Does that mean anything for the above seq_file_path()?

Hi Kees.

Thanks for taking a look. The comment above says the "files" pointer can be stale. It doesn't affect our use of "file" here. seq_show() takes the reference with get_file() so "file" wouldn't be destroyed from under us.

Thanks, Kalesh

-- Kees Cook