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Date:   Wed, 13 May 2020 12:00:10 -0700 (PDT)
Message-Id: <20200513.120010.124458176293400943.davem@davemloft.net>
To:     madhuparnabhowmik10@gmail.com
Cc:     kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, kuba@kernel.org,
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Subject: Re: [PATCH] Fix suspicious RCU usage warning
From:   David Miller <davem@davemloft.net>
In-Reply-To: <20200513061610.22313-1-madhuparnabhowmik10@gmail.com>
References: <20200513061610.22313-1-madhuparnabhowmik10@gmail.com>
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From: madhuparnabhowmik10@gmail.com
Date: Wed, 13 May 2020 11:46:10 +0530

> From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
> 
> This patch fixes the following warning:
> 
> =============================
> WARNING: suspicious RCU usage
> 5.7.0-rc4-next-20200507-syzkaller #0 Not tainted
> -----------------------------
> net/ipv6/ip6mr.c:124 RCU-list traversed in non-reader section!!
> 
> ipmr_new_table() returns an existing table, but there is no table at
> init. Therefore the condition: either holding rtnl or the list is empty
> is used.
> 
> Suggested-by: Jakub Kicinski <kuba@kernel.org>
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
> 
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

Please only provide one signoff line.

Please provide a proper Fixes: tag for this bug fix.

And finally, please make your Subject line more appropriate.  It must
first state the target tree inside of the "[PATCH]" area, the two choices
are "[PATCH net]" and "[PATCH net-next]" and it depends upon which tree
this patch is targetting.

Then your Subject line should also be more descriptive about exactly the
subsystem and area the change is being made to, for this change for
example you could use something like:

	ipv6: Fix suspicious RCU usage warning in ip6mr.

Also, obviously, there are also syzkaller tags you can add to the
commit message as well.