Re: [PATCH net] net/smc: Avoid setting clcsock options after clcsock released

[Wen Gu <guwen@xxxxxxxxxxxxxxxxx>]

On 2022/1/12 3:11 pm, dust.li wrote:
> On Mon, Jan 10, 2022 at 05:38:25PM +0800, Wen Gu wrote:
> > This patch tries to fix it by holding clcsock_release_lock and
> > checking whether clcsock has already been released. In case that
> > a crash of the same reason happens in smc_getsockopt(), this patch
> > also checkes smc->clcsock in smc_getsockopt().

> > @@ -2509,13 +2515,21 @@ static int smc_getsockopt(struct socket *sock, int level, int optname,
> > 			  char __user *optval, int __user *optlen)
> > {
> > 	struct smc_sock *smc;
> > +	int rc;
> >
> > 	smc = smc_sk(sock->sk);
> > +	mutex_lock(&smc->clcsock_release_lock);
> > +	if (!smc->clcsock) {
> > +		mutex_unlock(&smc->clcsock_release_lock);
> > +		return -EBADF;
> > +	}
> > 	/* socket options apply to the CLC socket */
> > 	if (unlikely(!smc->clcsock->ops->getsockopt))
> Missed a mutex_unlock() here ?
>
> > 		return -EOPNOTSUPP;

Thanks for pointing it out. Will add an additional mutex_unlock().

Thanks,
Wen Gu