Re: [PATCH net] netfilter: nf_log: don't hold nf_log_mutex during user access

From: Pablo Neira Ayuso
Date: Tue Jun 26 2018 - 12:05:27 EST


On Mon, Jun 25, 2018 at 05:22:00PM +0200, Jann Horn wrote:
> The old code would indefinitely block other users of nf_log_mutex if
> a userspace access in proc_dostring() blocked e.g. due to a userfaultfd
> region. Fix it by moving proc_dostring() out of the locked region.
>
> This is a followup to commit 266d07cb1c9a ("netfilter: nf_log: fix
> sleeping function called from invalid context"), which changed this code
> from using rcu_read_lock() to taking nf_log_mutex.

Applied.