On Mon, May 05, 2025 at 11:48:43AM -0700, Kuniyuki Iwashima wrote:
> From: Christian Brauner <brauner@xxxxxxxxxx>
> Date: Mon, 05 May 2025 13:13:42 +0200
> > @@ -801,6 +846,40 @@ void do_coredump(const kernel_siginfo_t *siginfo)
> > }
> > break;
> > }
> > + case COREDUMP_SOCK: {
> > + struct file *file __free(fput) = NULL;
> > +#ifdef CONFIG_UNIX
> > + struct socket *socket;
> > +
> > + /*
> > + * It is possible that the userspace process which is
> > + * supposed to handle the coredump and is listening on
> > + * the AF_UNIX socket coredumps. Userspace should just
> > + * mark itself non dumpable.
> > + */
> > +
> > + retval = sock_create_kern(&init_net, AF_UNIX, SOCK_STREAM, 0, &socket);
> > + if (retval < 0)
> > + goto close_fail;
> > +
> > + file = sock_alloc_file(socket, 0, NULL);
> > + if (IS_ERR(file)) {
> > + sock_release(socket);
> > + retval = PTR_ERR(file);
> > + goto close_fail;
> > + }
> > +
> > + retval = kernel_connect(socket,
> > + (struct sockaddr *)(&coredump_unix_socket),
> > + COREDUMP_UNIX_SOCKET_ADDR_SIZE, 0);
>
> This blocks forever if the listener's accept() queue is full.
>
> I think we don't want that and should pass O_NONBLOCK.
>
> To keep the queue clean is userspace responsibility, and we don't
> need to care about a weird user.
That seems fine to me. I've changed that.
