From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: Su Yanjun <suyanjun218@163.com>,
pablo@netfilter.org, kadlec@blackhole.kfki.hu, fw@strlen.de,
davem@davemloft.net, netfilter-devel@vger.kernel.org,
coreteam@netfilter.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: suyj.fnst@cn.fujitsu.com
Subject: Re: [PATCH] netfilter: nf_ct_helper: Fix possible panic when nf_conntrack_helper_unregister is used in an unloadable module
Date: Fri, 1 Mar 2019 11:43:43 +0300 [thread overview]
Message-ID: <e420b6c0-bebf-a2fc-a2ee-7b3e0023d833@cogentembedded.com> (raw)
In-Reply-To: <1551419766-1039-1-git-send-email-suyanjun218@163.com>
Hello!
On 01.03.2019 8:56, Su Yanjun wrote:
> From: Su Yanjun <suyj.fnst@cn.fujitsu.com>
>
> Because nf_conntrack_helper_unregister maybe used in an unloadable module,
> it uses 'synchronize_rcu' which may cause kernel panic.
>
> According to the artical:
Article?
> RCU and Unloadable Modules
> https://lwn.net/Articles/217484/
>
> When we have a heavy rcu callback load, then some of the callbacks might be
> deferred in order to allow other processing to proceed. sychnorize_rcu does
> not wait rcu callback complete and module may be unloaded before callback
> done.
>
> This patch uses rcu_barrier instead of synchronize_rcu will prevent this
^ that/which missed?
> situation.
>
> Signed-off-by: Su Yanjun <suyj.fnst@cn.fujitsu.com>
[...]
MBR, Sergei
next prev parent reply other threads:[~2019-03-01 8:44 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-01 5:56 [PATCH] netfilter: nf_ct_helper: Fix possible panic when nf_conntrack_helper_unregister is used in an unloadable module Su Yanjun
2019-03-01 8:43 ` Sergei Shtylyov [this message]
2019-03-01 9:08 ` Su Yanjun <suyj.fnst@cn.fujitsu.com>
2019-03-08 15:59 ` Pablo Neira Ayuso
2019-03-14 3:20 ` Su Yanjun <suyj.fnst@cn.fujitsu.com>
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