From: Florian Westphal <fw@strlen.de>
To: shaochun chen <cscnull@gmail.com>
Cc: Florian Westphal <fw@strlen.de>,
Pablo Neira Ayuso <pablo@netfilter.org>,
David Miller <davem@davemloft.net>,
kadlec <kadlec@blackhole.kfki.hu>,
"johannes.berg" <johannes.berg@intel.com>,
jason <Jason@zx2c4.com>, ktkhai <ktkhai@virtuozzo.com>,
"lucien.xin" <lucien.xin@gmail.com>,
"xiyou.wangcong" <xiyou.wangcong@gmail.com>,
dsahern <dsahern@gmail.com>,
netfilter-devel <netfilter-devel@vger.kernel.org>,
tom <tom@quantonium.net>, netdev <netdev@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] netlink: fix memory leak of dump
Date: Mon, 23 Jul 2018 12:59:15 +0200 [thread overview]
Message-ID: <20180723105915.a6vx5t7htcclez3k@breakpoint.cc> (raw)
In-Reply-To: <CAKDdixBBd08eKvk-hJtwPy46u2uzihRCh_KdEMF3xG1ZJ6oNsg@mail.gmail.com>
shaochun chen <cscnull@gmail.com> wrote:
> I have a question: we will try_module_get in __netlink_dump_start(),
Thats too late, we release rcu read lock before this, so the module
implementing ->dump might have been removed already.
> but why we need to call try_module_get again in nft_netlink_dump_start ??
Its the other way around.
This is the first try_module_get; at this point we still hold rcu read
lock.
If nf_tables module is being removed, try_module_get will fail and
we can error out.
If it succeeds, its safe to drop the rcu read lock.
prev parent reply other threads:[~2018-07-23 10:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-22 14:33 [PATCH] netlink: fix memory leak of dump Shaochun Chen
2018-07-22 16:39 ` Florian Westphal
2018-07-22 17:07 ` David Miller
2018-07-22 18:09 ` Florian Westphal
2018-07-23 2:05 ` shaochun chen
2018-07-23 9:15 ` Pablo Neira Ayuso
2018-07-23 9:28 ` Florian Westphal
2018-07-23 9:38 ` Pablo Neira Ayuso
2018-07-23 9:42 ` Florian Westphal
2018-07-23 9:47 ` Pablo Neira Ayuso
2018-07-23 10:51 ` Florian Westphal
2018-07-23 9:52 ` shaochun chen
2018-07-23 10:34 ` shaochun chen
2018-07-23 10:43 ` Pablo Neira Ayuso
2018-07-23 10:59 ` Florian Westphal [this message]
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