Re: [PATCH] twist: allow converting pr_devel()/pr_debug() into printk(KERN_DEBUG)

From: Joe Perches
Date: Sun May 24 2020 - 13:38:07 EST


On Sun, 2020-05-24 at 23:50 +0900, Tetsuo Handa wrote:
> syzbot found a NULL pointer dereference bug inside mptcp_recvmsg() due to
> ssock == NULL, but this bug manifested inside selinux_socket_recvmsg()
> because pr_debug() was no-op [1].
>
> pr_debug("fallback-read subflow=%p",
> mptcp_subflow_ctx(ssock->sk));
> copied = sock_recvmsg(ssock, msg, flags);

> Since console loglevel used by syzkaller will not print KERN_DEBUG
> messages to consoles, always evaluating pr_devel()/pr_debug() messages
> will not cause too much console output. Thus, let's allow fuzzers to
> always evaluate pr_devel()/pr_debug() messages.

While I think this is rather unnecessary,
what about dev_dbg/netdev_dbg/netif_dbg et al ?