On Thu, 2024-03-07 at 10:57 +0100, Jan Karcher wrote:
> We think it might be an option to secure the path in this function with
> the smc->clcsock_release_lock.
>
> ```
> lock_sock(&smc->sk);
> if (smc->use_fallback) {
> if (!smc->clcsock) {
> release_sock(&smc->sk);
> return -EBADF;
> }
> + mutex_lock(&smc->clcsock_release_lock);
> answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
> + mutex_unlock(&smc->clcsock_release_lock);
> release_sock(&smc->sk);
> return answ;
> }
> ```
>
> What do yo think about this?
You're trying to fix it on the wrong path. FIOASYNC is a generic rather
than protocol-specific thing. So userspace 'ioctl(sock, FIOASYNC, [])'
call is handled with:
-> sys_ioctl()
-> do_vfs_ioctl()
-> ioctl_fioasync()
-> filp->f_op->fasync() (which is sock_fasync() for all sockets)
rather than 'sock->ops->ioctl(...)'.
Dmitry
